WO2013070240A1 - Dual plunger rod for controlled transport in an injection molding system - Google Patents

Abstract

Disclosed is an injection molding system including a first plunger rod and a second plunger rod configured to move or transport molten material from a melt zone and into a mold. The first and second plunger rods are configured to control and contain the molten material therebetween while moving. The second plunger rod can also be positioned relative to the mold to apply pressure on one side of the mold as the first plunger rod pushes molten material into the mold on an opposite side to force the material into the mold cavity. The second plunger rod can further be used to eject a molded (bulk amorphous) object from the mold. The rods can move in a longitudinal direction (e.g., horizontally) between the melt zone and mold along a longitudinal axis.

Description

DUAL PLUNGER ROD FOR CONTROLLED TRANSPORT IN AN INJECTION

MOLDING SYSTEM

FIELD

(00011 The present disclosure is generally related to an injection molding system for melting material and molding objects from molten material .

BACKGROUND

[0002) Some conventional casting or molding machines inc lude a single plunger rod that moves and packs material into a mold using increased force. However, when molding or casting a high aspect ratio part using amorphous alloys in such a system, the molded part tends to be non-uniform and/or crystallized because the quenching rate of the mold is insufficient (e.g. , the material cools too quickly on one side, and does not cool quickly enough on other side(s) (e.g., plunger side)). Increasing the speed or force of the single plunger rod does not reduce this problem.

|0003) Additionally, in horizontal injection systems, the molten material has to be retained in the melt zone so that it does not mix too much or cool too quickly.

SUMMARY

[0004] A proposed solution according to embodiments herein for improving molded objects or parts is to use bulk-sol idifying amorphous al loys.

[0005| One aspect of this disclosure provides an injection molding system having a melt zone configured to melt meltable material received therein and a dual plunger rod assembly. The dual plunger rod assembly includes a first plunger rod and a second plunger rod, at least the first plunger rod being configured to move molten material from the melt zone and into a mold. The dual plunger rod assembly and the melt zone are provided in-line. The first and second plunger rods are configured to move along a longitudinal axis, such that

I at least the first plunger rod is moved in a longitudinal direction from the melt zone to move the molten material into the mold.

|0006| Another aspect provides an injection molding system including a melt zone configured to melt meltable material received therein, a mold configured to receive molten material therein for molding, and a first plunger rod and a second plunger rod configured to move relative to each other. The first plunger rod and the second plunger rod are configured to move the molten material from the melt zone and into the mold.

|0007) Yet another aspect provides a method of molding an object from meltable material using an injection molding system. The system includes a melt zone configured to melt the meltable material received therein and a plunger rod assembly having a first plunger rod and a second plunger rod, the assembly configured to move molten material from the melt zone and into a mold. The method includes: melting a meltable material in the melt zone, and moving the molten material from the melt zone and into the mold, and the first plunger rod and the second plunger rod are configured to contain the molten material therebetween during movement of the molten material towards the mold.

BRIEF DESCRIPTION OF THE DRAWINGS

|0008) FIG. 1 provides a temperature-viscosity diagram of an exemplary bulk solidifying amorphous alloy.

[0009| FIG. 2 provides a schematic of a time-temperature-transformation (TTT) diagram for an exemplary bulk solidifying amorphous alloy.

100010) FIG. 3 illustrates an injection molding system with a dual plunger rod assembly in accordance with an embodiment of the disclosure.

10001 11 FIGS. 4-6 illustrate movement of the dual plunger rod assembly relative to a melt zone, mold, and each other in the injection system of FIG . 3, in accordance with an embodiment. 100012| FIG. 7 illustrates a detailed view of using a second plunger rod to assist in injecting molten material into a cavity of a mold being moved therein by a first plunger rod, in accordance with an embodiment.

|00013| FIG . 8 illustrated a detailed view of using a second plunger rod to eject a molded object from the mold in accordance with an embodiment.

DETAILED DESCRIPTION

(00014) All publications, patents, and patent appl ications cited in this Specification are hereby incorporated by reference in their entirety.

|00015| The articles "a" and "an" are used herein to refer to one or to more than one (i .e. , to at least one) of the grammatical object of the article. By way of example, "a polymer resin" means one polymer resin or more than one polymer resin. Any ranges cited herein are inclusive. The terms "substantially" and "about" used throughout this Specification are used to describe and account for smal l fluctuations. For example, they can refer to less than or equal to ±5%, such as less than or equal to ±2%, such as less than or equal to ± 1 %, such as less than or equal to ±0.5%, such as less than or equal to ±0.2%, such as less than or equal to ±0. 1 %, such as less than or equal to ±0.05%.

|00016| Bulk-solidi fying amorphous alloys, or bulk metal lic glasses ("BMG"), are a recently developed c lass of metall ic materials. These al loys may be solidified and cooled at relatively slow rates, and they retain the amorphous, non-crystalline (i .e. , glassy) state at room temperature. Amorphous alloys have many superior properties than their crystalline counterparts. However, if the cooling rate is not sufficiently high, crystals may form inside the alloy during cool ing, so that the benefits of the amorphous state can be lost. For example, one challenge with the fabrication of bulk amorphous alloy parts is partial crystallization of the parts due to either slow cooling or impurities in the raw alloy material. As a high degree of amorphicity (and, conversely, a low degree of crystallinity) is desirable in BMG parts, there is a need to develop methods for casting BMG parts having controlled amount of amorphicity. |00017| Figure 1 (obtained from U.S. Pat. No. 7,575,040) shows a viscosity- temperature graph of an exemplary bulk solidifying amorphous alloy, from the VlT-001 series of Zr-Ti-Ni-Cu-Be family manufactured by Liquidmeial Technology. It should be noted that there is no clear l iquid/solid transformation for a bulk sol idifying amorphous metal during the formation of an amorphous solid. The molten alloy becomes more and more viscous with increasing undercooling until it approaches sol id form around the glass transition temperature. Accordingly, the temperature of solidification front for bulk solidifying amorphous alloys can be around glass transition temperature, where the al loy wil l practically act as a solid for the purposes of pulling out the quenched amorphous sheet product.

(00018) Figure 2 (obtained from U.S. Pat. No. 7,575,040) shows the time-temperature- transformation (TTT) cooling curve of an exemplary bulk sol idifying amorphous alloy, or TTT diagram. Bulk-solidifying amorphous metals do not experience a liquid/solid crystal lization transformation upon cooling, as with conventional metals. Instead, the highly fluid, non crystalline form of the metal found at high temperatures (near a "melting temperature" Tm) becomes more viscous as the temperature is reduced (near to the glass transition temperature Tg), eventually taking on the outward physical properties of a conventional sol id.

(00019) Even though there is no liquid/crystallization transformation for a bul k solidifying amorphous metal, a "melting temperature" Tm may be defined as the

thermodynamic liquidus temperature of the corresponding crystalli ne phase. Under this regime, the viscosity of bulk-solidifying amorphous alloys at the melting temperature could lie in the range of about 0. 1 poise to about 10,000 poise, and even sometimes under 0.01 poise. A lower viscosity at the "melting temperature" would provide faster and complete filling of intricate portions of the shell/mold with a bulk sol idifying amorphous metal for forming the BMG parts. Furthermore, the cooling rate of the molten metal to form a BMG part has to such that the time-temperature profile during cooling does not traverse through the nose-shaped region bounding the crystallized region in the TTT diagram of Figure 2. In Figure 2, Tnose is the critical crystallization temperature Tx where crystallization is most rapid and occurs in the shortest time scale. |00020) The supercooled liquid region, the temperature region between Tg and Tx is a manifestation of the extraordinary stability against crystallization of bulk solidification alloys. In this temperature region the bulk solidi fying alloy can exist as a high viscous liquid. The viscosity of the bulk solidifying alloy in the supercooled liquid region can vary between l O¹² Pa s at the glass transition temperature down to 10⁵ Pa s at the crystallization temperature, the high temperature limit of the supercooled liquid region. Liquids with such viscosities can undergo substantial plastic strain under an applied pressure. The embodiments herein make use of the large plastic formabil ity in the supercooled liquid region as a forming and separating method.

|00021 1 One needs to clarify something about Tx. Technically, the nose-shaped curve shown in the TTT diagram describes Tx as a function of temperature and time. Thus, regardless of the trajectory that one takes while heating or cooling a metal alloy, when one hits the TTT curve, one has reached Tx. In Figure 2, Tx is shown as a dashed line as Tx can vary from close to Tm to close to Tg.

100022] The schematic TTT diagram of Figure 2 shows processing methods of die casting from at or above Tm to below Tg without the time-temperature trajectory (shown as ( 1 ) as an example trajectory) hitting the TTT curve. During die casting, the forming takes place substantially simultaneously with fast cooling to avoid the trajectory hitting the TTT curve. The processing methods for superplastic forming (SPF) from at or below Tg to below Tm without the time-temperature trajectory (shown as (2), (3) and (4) as example trajectories) hitting the TTT curve. In SPF, the amorphous BMG is reheated into the supercooled liquid region where the available processing window could be much larger than die casting, resulting in better controllability of the process. The SPF process does not require fast cooling to avoid crystal lization during cooling. Also, as shown by example trajectories (2), (3) and (4), the SPF can be carried out with the highest temperature during SPF being above Tnose or below Tnose, up to about Tm. If one heats up a piece of amorphous alloy but manages to avoid hitting the TTT curve, you have heated "between Tg and Tm", but one would have not reached Tx.

|00023 J Typical differential scanning calorimeter (DSC) heating curves of bulk- solidifying amorphous alloys taken at a heating rate of 20 C/min describe, for the most part, a particular trajectory across the TTT data where one would likely see a Tg at a certain temperature, a Tx when the DSC heating ramp crosses the TTT crystallization onset, and eventually melting peaks when the same trajectory crosses the temperature range for melting. If one heats a bulk-solidifying amorphous alloy at a rapid heating rate as shown by the ramp up portion of trajectories (2), (3) and (4) in Figure 2, then one could avoid the TTT curve entirely, and the DSC data would show a glass transition but no Tx upon heating. Another way to think about it is trajectories (2), (3) and (4) can fall anywhere in temperature between the nose of the TTT curve (and even above it) and the Tg line, as long as it does not hit the crystallization curve. That just means that the horizontal plateau in trajectories might get much shorter as one increases the processing temperature.

Phase

(00024) The term "phase" herein can refer to one that can be found in a thermodynamic phase diagram. A phase is a region of space (e.g. , a thermodynamic system) throughout which all physical properties of a material are essentially uniform. Examples of physical properties include density, index of refraction, chemical composition and lattice periodic ity. A simple description of a phase is a region of material that is chemically uniform, physically distinct, and/or mechanically separable. For example, in a system consisting of ice and water in a glass jar, the ice cubes are one phase, the water is a second phase, and the humid air over the water is a third phase. The glass of the jar is another separate phase. A phase can refer to a solid solution, which can be a binary, tertiary, quaternary, or more, solution, or a compound, such as an intermetallic compound. As another example, an amorphous phase is distinct from a crystalline phase.

Metal, Transition Metal, and Non-metal

|00025| The term "metal" refers to an electropositive chemical element. The term

"element" in this Specification refers generally to an element that can be found in a Periodic Table. Physically, a metal atom in the ground state contains a partially fil led band with an empty state close to an occupied state. The term "transition metal" is any of the metallic elements within Groups 3 to 1 2 in the Periodic Table that have an incomplete inner electron shell and that serve as transitional links between the most and the least electropositive in a series of elements. Transition metals are characterized by multiple valences, colored compounds, and the ability to form stable complex ions. The term "nonmetal" refers to a chemical element that does not have the capacity to lose electrons and form a positive ion.

[00026] Depending on the application, any suitable nonmetal elements, or their combinations, can be used. The alloy (or "alloy composition") can comprise multiple nonmetal elements, such as at least two, at least three, at least four, or more, nonmetal elements. A nonmetal element can be any element that is found in Groups 1 3- 1 7 in the Periodic Table. For example, a nonmetal element can be any one of F, CI, Br, I, At, O, S, Se, Te, Po, N, P, As, Sb, Bi, C, Si, Ge, Sn, Pb, and B. Occasionally, a nonmetal element can also refer to certain metalloids (e.g., B, Si , Ge, As, Sb, Te, and Po) in Groups 1 3- 1 7. In one embodiment, the nonmetal elements can include B, Si, C, P, or combinations thereof.

Accordingly, for example, the al loy can comprise a boride, a carbide, or both .

100027) A transition metal element can be any of scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, yttrium, zirconium, niobium, molybdenum, technetium, ruthenium, rhodium, palladium, silver, cadmium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum, gold, mercury, rutherfordium, dubnium, seaborgium, bohrium, hassium, meitnerium, ununnilium, unununium, and ununbium. In one embodiment, a BMG containing a transition metal element can have at least one of Sc , Y, La, Ac , Ti , Zr, H f, V, Nb, Ta, Cr, Mo, W, Mn, Tc , Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, and Hg. Depending on the application, any suitable transitional metal elements, or their combinations, can be used. The alloy composition can comprise multiple transitional metal elements, such as at least nvo, at least three, at least four, or more, transitional metal elements.

|00028) The presently described alloy or alloy "sample" or "specimen" alloy can have any shape or size. For example, the alloy can have a shape of a particulate, which can have a shape siich as spherical, el lipsoid, wire-like, rod-like, sheet-like, flake-like, or an irregular shape. The particulate can have any size. For example, it can have an average diameter of between about I micron and about 100 microns, such as between about 5 microns and about 80 microns, such as between about 10 microns and about 60 microns, such as between about 1 5 microns and about 50 microns, such as between about 1 5 microns and about 45 microns, such as between about 20 microns and about 40 microns, such as between about 25 microns and about 35 microns. For example, in one embodiment, the average diameter of the particulate is between about 25 microns and about 44 microns. In some embodiments, smaller particulates, such as those in the nanometer range, or larger particulates, such as those bigger than 100 microns, can be used.

100029) The alloy sample or specimen can also be of a much larger dimension. For example, it can be a bulk structural component, such as an ingot, housing/casing of an electronic device or even a portion of a structural component that has dimensions in the mi llimeter, centimeter, or meter range.

Solid solution

|00030] The term "sol id solution" refers to a solid form of a solution. The term "solution" refers to a mixture of two or more substances, which may be solids, liquids, gases, or a combination of these. The mixture can be homogeneous or heterogeneous. The term "mixture" is a composition of two or more substances that are combined with each other and are generally capable of being separated. Generally, the two or more substances are not chemically combined wi th each other.

Alloy

[00031 ] In some embodiments, the alloy composition described herein can be fully alloyed. In one embodiment, an "alloy" refers to a homogeneous mixture or solid solution of two or more metals, the atoms of one replacing or occupying interstitial positions between the atoms of the other; for example, brass is an alloy of zinc and copper. An alloy, in contrast to a composite, can refer to a partial or complete solid solution of one or more elements in a metal matrix, such as one or more compounds in a metallic matrix . The term alloy herein can refer to both a complete solid solution alloy that can give single sol id phase

microstrucrure and a partial solution that can give two or more phases. An alloy composition described herein can refer to one comprising an alloy or one comprising an alloy-containing composite.

|00032| Thus, a fully alloyed alloy can have a homogenous distribution of the constituents, be it a solid solution phase, a compound phase, or both. The term "fully alloyed" used herein can account for minor variations within the error tolerance. For example, it can refer to at least 90% alloyed, such as at least 95% alloyed, such as at least 99% alloyed, such as at least 99.5% alloyed, such as at least 99.9% alloyed. The percentage herein can refer to either volume percent or weight percentage, depending on the context. These percentages can be balanced by impurities, which can be in terms of composition or phases that are not a part of the alloy.

Amorphous or non-cn'stalline solid

|00033| An "amorphous" or "non-crystalline solid" is a solid that lacks lattice periodicity, which is characteristic of a crystal. As used herein, an "amorphous solid" includes "glass" which is an amorphous solid that softens and transforms into a liquid-like state upon heating through the glass transition. Generally, amorphous materials lack the long-range order characteristic of a crystal, though they can possess some short-range order at the atomic length scale due to the nature of chemica l bonding. The distinction between amorphous solids and crystall ine solids can be made based on lattice periodicity as determined by structural characterization techniques such as x-ray diffraction and transmission electron microscopy.

[00034] The terms "order" and "disorder" designate the presence or absence of some symmetry or correlation in a many-particle system. The terms "long-range order" and "short- range order" distinguish order in materials based on length scales.

100035) The strictest form of order in a solid is lattice periodicity: a certain pattern (the arrangement of atoms in a unit cell) is repeated again and again to form a translationally invariant ti ling of space . This is the defining property of a crystal . Possible symmetries have been classified in 14 Bravais lattices and 230 space groups.

[00036) Lattice periodicity implies long-range order. If only one unit cell is known, then by virtue of the translational symmetry it is possible to accurately predict all atomic positions at arbitrary distances. The converse is generally true, except, for example, in quasi-crystals that have perfectly deterministic ti lings but do not possess lattice periodicity. 100037) Long-range order characterizes physical systems in which remote portions of the same sample exhibit correlated behavior. This can be expressed as a correlation function, namely the spin-spin correlation function: 1 ) — {s(x , s(x )) .

100038] In the above function, s is the spin quantum number and x is the distance function within the particular system. This function is equal to unity when x = x' and decreases as the distance | x— ' | increases. Typically, it decays exponentially to zero at large distances, and the system is considered to be disordered. I f, however, the correlation function decays to a constant value at large | x - ' |, then the system can be said to possess long-range order. I f it decays to zero as a power of the distance, then it can be called quasi-long-range order. Note that what constitutes a large value of | x - ' | is relative.

100039) A system can be said to present quenched disorder when some parameters defining its behavior are random variables that do not evolve with time (i.e., they are quenched or frozen) - e.g. , spin glasses. It is opposite to annealed disorder, where the random variables are allowed to evolve themselves. Embodiments herein include systems comprising quenched disorder.

|00040| The alloy described herein can be crystalli ne, partially crystalline, amorphous, or substantially amorphous. For example, the al loy sample/specimen can include at least some crystallinity, with grains/crystals having sizes in the nanometer and/or micrometer ranges. Alternatively, the alloy can be substantially amorphous, such as fully amorphous. In one embodiment, the alloy composition is at least substantially not amorphous, such as being substantially crystalline, such as being entirely crystalline.

[000411 In one embodiment, the presence of a crystal or a plurality of crystals in an otherwise amorphous alloy can be construed as a "crystall ine phase" therein. The degree of crystal l inity (or "crystall inity" for short in some embodiments) of an alloy can refer to the amount of the crystalline phase present in the alloy. The degree can refer to, for example, a fraction of crystals present in the alloy. The fraction can refer to volume fraction or weight fraction, depending on the context. A measure of how "amorphous" an amorphous alloy is can be amorphicify. Amorphicity can be measured in terms of a degree of crystallinity. For example, in one embodiment, an alloy having a low degree of crystallinity can be said to have a high degree of amorphicity. In one embodiment, for example, an alloy having 60 vol% crystalline phase can have a 40 vol% amorphous phase.

Amorphous alloy or amorphous metal

1000421 An "amorphous alloy" is an alloy having an amorphous content of more than 50% by volume, preferably more than 90% by volume of amorphous content, more preferably more than 95% by volume of amorphous content, and most preferably more than 99% to almost 100% by volume of amorphous content. Note that, as described above, an alloy high in amorphicity is equivalently low in degree of crystal linity. An "amorphous metal" is an amorphous metal material with a disordered atomic-scale structure. In contrast to most metals, which are crystalline and therefore have a highly ordered arrangement of atoms, amorphous alloys are non-crystalline. Materials in which such a disordered structure is produced directly from the l iquid state during cooling are sometimes referred to as "glasses." Accordingly, amorphous metals are commonly referred to as "metall ic glasses" or "glassy metals." In one embodiment, a bulk metallic glass ("BMG") can refer to an alloy, of which the microstructure is at least partially amorphous. However, there are several ways besides extremely rapid cooling to produce amorphous metals, including physical vapor deposition, solid-state reaction, ion irradiation, melt spinning, and mechanical alloying. Amorphous alloys can be a single class of materials, regardless of how they are prepared.

|000431 Amorphous metals can be produced through a variety of quick-cooling methods. For instance, amorphous metals can be produced by sputtering molten metal onto a spinning metal disk. The rapid cool ing, on the order of millions of degrees a second, can be too fast for crystals to form, and the material is thus "locked in" a glassy state. Also, amorphous metals/alloys can be produced with critical cool ing rates low enough to allow formation of amorphous structures in thick layers - e.g., bulk metallic glasses.

100044] The terms "bulk metallic glass" ("BMG"), bulk amorphous alloy ("BAA"), and bulk solidifying amorphous alloy are used interchangeably herein. They refer to amorphous alloys having the smal lest dimension at least in the mill imeter range. For example, the dimension can be at least about 0.5 mm, such as at least about 1 mm, such as at least about 2 mm, such as at least about 4 mm, such as at least about 5 mm, such as at least about 6 mm, such as at least about 8 mm, such as at least about 10 mm, such as at least about 12 mm.

I I Depending on the geometry, the dimension can refer to the diameter, radius, thickness, width, length, etc . A BMG can also be a metallic glass having at least one dimension in the centimeter range, such as at least about 1 .0 cm, such as at least about 2.0 cm, such as at least about 5.0 cm, such as at least about 10.0 cm. In some embodiments, a BMG can have at least one dimension at least in the meter range. A BMG can take any of the shapes or forms described above, as related to a metallic glass. Accordingly, a BMG described herein in some embodiments can be different from a thin film made by a conventional deposition technique in one important aspect - the former can be of a much larger dimension than the latter.

|00045] Amorphous metals can be an alloy rather than a pure metal . The alloys may contain atoms of signi ficantly different sizes, leading to low free volume (and therefore having viscosity up to orders of magnitude higher than other metals and alloys) in a molten state. The viscosity prevents the atoms from moving enough to form an ordered lattice. The material structure may result in low shrinkage during cooling and resistance to plastic deformation. The absence of grain boundaries, the weak spots of crystalline materials in some cases, may, for example, lead to better resistance to wear and corrosion. In one embodiment, amorphous metals, while technically glasses, may also be much tougher and less brittle than oxide glasses and ceramics.

(00046) Thermal conductivity of amorphous materials may be lower than that of their crystalline counterparts. To achieve formation of an amorphous structure even during slower cooling, the alloy may be made of three or more components, leading to complex crystal units with higher potential energy and lower probability of formation. The formation of amorphous alloy can depend on several factors: the composition of the components of the alloy; the atomic radius of the components (preferably with a signi ficant difference of over 12% to achieve high packing density and low free volume); and the negative heat of mixing the combination of components, inhibiting crystal nucleation and prolonging the time the molten metal stays in a supercooled state. However, as the formation of an amorphous alloy is based on many di fferent variables, it can be difficult to make a prior determination of whether an alloy composition would form an amorphous alloy. 100047) Amorphous alloys, for example, of boron, silicon, phosphorus, and other glass formers with magnetic metals (iron, cobalt, nickel) may be magnetic, with low coercivity and high electrical resistance. The high resistance leads to low losses by eddy currents when subjected to alternating magnetic fields, a property useful, for example, as transformer magnetic cores.

|00048| Amorphous alloys may have a variety of potentially useful properties. In particular, they tend to be stronger than crystalline alloys of similar chemical composition, and they can sustain larger reversible ("elastic") deformations than crystalline alloys.

Amorphous metals derive their strength directly from their non-crystalline structure, which can have none of the defects (such as dislocations) that l imit the strength of crystalline alloys. For example, one modern amorphous metal, known as Vitreloy™, has a tensile strength that is almost twice that of high-grade titanium. In some embodiments, metallic glasses at room temperature are not ductile and tend to fail suddenly when loaded in tension, which l imits the material applicability in rel iability-critical applications, as the impending failure is not evident. Therefore, to overcome this challenge, metal matrix composite materials having a metallic glass matrix containing dendritic particles or fibers of a ductile crystal line metal can be used. Alternatively, a BMG low in element(s) that tend to cause embitterment (e.g. , Ni) can be used. For example, a Ni-free BMG can be used to improve the ductility of the BMG.

[00049] Another useful property of bulk amorphous alloys is that they can be true glasses; in other words, they can soften and flow upon heating. This can allow for easy processing, such as by injection molding, in much the same way as polymers. As a result, amorphous alloys can be used for making sports equipment, medical devices, electronic components and equipment, and thin films. Thin films of amorphous metals can be deposited as protective coatings via a high velocity oxygen fuel technique.

(00050) A material can have an amorphous phase, a crystalline phase, or both. The amorphous and crystalline phases can have the same chemical composition and differ only in the microstructure - i.e. , one amorphous and the other crystal line. Microstructure in one embodiment refers to the structure of a material as revealed by a microscope at 25X magni fication or higher. Alternatively, the two phases can have di fferent chemical compositions and microstructures. For example, a composition can be partially amorphous, substantially amorphous, or completely amorphous.

[00051 ] As described above, the degree of amorphicity (and conversely the degree of crystallinity) can be measured by fraction of crystals present in the alloy. The degree can refer to volume fraction of weight fraction of the crystalline phase present in the alloy. A partially amorphous composition can refer to a composition of at least about 5 vol% of which is of an amorphous phase, such as at least about 10 vol%, such as at least about 20 vol%, such as at least about 40 vol%, such as at least about 60 vol%, such as at least about 80 vol%, such as at least about 90 vol%. The terms "substantially" and "about" have been defined elsewhere in this application. Accordingly, a composition that is at least substantially amorphous can refer to one of which at least about 90 vol% is amorphous, such as at least about 95 vol%, such as at least about 98 vol%, such as at least about 99 vol%, such as at least about 99.5 vol%, such as at least about 99.8 vol%, such as at least about 99.9 vol%. In one embodiment, a substantially amorphous composition can have some incidental, insigni ficant amount of crystalline phase present therein.

1000521 In one embodiment, an amorphous alloy composition can be homogeneous with respect to the amorphous phase. A substance that is uni form in composition is homogeneous. This is in contrast to a substance that is heterogeneous. The term "composition" refers to the chemical composition and/or microstructure in the substance. A substance is homogeneous when a volume of the substance is divided in half and both halves have substantially the same composition. For example, a particulate suspension is homogeneous when a volume of the particulate suspension is divided in half and both halves have substantially the same volume of particles. However, it might be possible to see the individual particles under a microscope. Another example of a homogeneous substance is air where different ingredients therein are equally suspended, though the partic les, gases and l iquids in air can be analyzed separately or separated from air.

[000531 A composition that is homogeneous with respect to an amorphous alloy can refer to one having an amorphous phase substantially uniformly distributed throughout its microstructure. In other words, the composition macroscopically comprises a substantially uniformly distributed amorphous alloy throughout the composition. In an alternative embodiment, the composition can be of a composite, having an amorphous phase having therein a non-amorphous phase. The non-amorphous phase can be a crystal or a plurality of crystals. The crystals can be in the form of particulates of any shape, such as spherical, ellipsoid, wire-like, rod-l ike, sheet-like, flake-like, or an irregular shape. In one embodiment, it can have a dendritic form. For example, an at least partially amorphous composite composition can have a crystalline phase in the shape of dendrites dispersed in an amorphous phase matrix; the dispersion can be uniform or non-uni form, and the amorphous phase and the crystal line phase can have the same or a different chemical composition. In one embodiment, they have substantially the same chemical composition. In another embodiment, the crystalline phase can be more ductile than the BMG phase.

(00054] The methods described herein can be applicable to any type of amorphous alloy. Similarly, the amorphous alloy described herein as a constituent of a composition or article can be of any type. The amorphous al loy can comprise the element Zr, H f, Ti, Cu, Ni , Pt, Pd, Fe, Mg, Au, La, Ag, Al, Mo, Nb, Be, or combinations thereof. Namely, the alloy can include any combination of these elements in its chemical formula or chemical composition. The elements can be present at di fferent weight or volume percentages. For example, an iron "based" alloy can refer to an alloy having a non-insignificant weight percentage of iron present therein, the weight percent can be, for example, at least about 20 wt%, such as at least about 40 wt%, such as at least about 50 wt%, such as at least about 60 \vt%, such as at least about 80 wt%. Alternatively, in one embodiment, the above-described percentages can be volume percentages, instead of weight percentages. Accordingly, an amorphous alloy can be zirconium-based, titanium-based, platinum-based, palladium-based, gold-based, silver-based, copper-based, iron-based, nickel-based, aluminum-based, molybdenum-based, and the like. The alloy can also be free of any of the aforementioned elements to suit a particular purpose. For example, in some embodiments, the alloy, or the composition including the alloy, can be substantially free of nickel, aluminum, titanium, beryllium, or combinations thereof. In one embodiment, the alloy or the composite is completely free of nickel, aluminum, titanium, beryllium, or combinations thereof.

(00055) For example, the amorphous alloy can have the formula (Zr, Ti)_a(Ni , Cu, Fe)_b(Be, A I , Si, B)c, wherein a, b, and c each represents a weight or atomic percentage. In one embodiment, a is in the range of from 30 to 75, b is in the range of from 5 to 60, and c is in the range of from 0 to 50 in atomic percentages. Alternatively, the amorphous alloy can have the formula (Zr, Ti)_a( i , Cu)b(Be)_c, wherein a, b, and c each represents a weight or atomic percentage. In one embodiment, a is in the range of from 40 to 75, b is in the range of from 5 to 50, and c is in the range of from 5 to 50 in atomic percentages. The alloy can also have the formula (Zr, Ti)_a(Ni, Cu)_b(Be)_c, wherein a, b, and c each represents a weight or atomic percentage. In one embodiment, a is in the range of from 45 to 65, b is in the range of from 7.5 to 35, and c is in the range of from 10 to 37.5 in atomic percentages. Alternatively, the alloy can have the formula (Zr)_a(Nb, Ti)b(Ni, Cu)_c(A l )a, wherein a, b, c, and d each represents a weight or atomic percentage. In one embodiment, a is in the range of from 45 to 65, b is in the range of from 0 to 10, c is in the range of from 20 to 40 and d is in the range of from 7.5 to 1 5 in atomic percentages. One exemplary embodiment of the aforedescribed alloy system is a Zr-Ti-Ni-Cu-Be based amorphous alloy under the trade name Vitreloy™, such as Vitreloy- 1 and Vitreloy- 101 , as fabricated by Liquidmetal Technologies, CA, USA. Some examples of amorphous alloys of the different systems are provided in Table 1 .

100056] The amorphous alloys can also be ferrous alloys, such as (Fe, Ni , Co) based alloys. Examples of such compositions are disclosed in U.S. Patent Nos. 6,325,868; 5,288,344; 5,368,659; 5,61 8,359; and 5,735 ,975, Inoue et a!. , Appl. Phys. Lett., Volume 7 1 , p 464 ( 1997), Shen el al. , Mater. Trans. , JI M, Volume 42, p 2 1 36 (2001 ), and Japanese Patent Application No. 2001 26277 (Pub. No. 2001 3032 1 8 A). One exemplary composition is

is. Another iron-based alloy system that can be used in the coating herein is disclosed in U.S. Patent Application

Publication No. 2010/0084052 , wherein the amorphous metal contains, for example, manganese ( 1 to 3 atomic %), yttrium (0. 1 to 10 atomic %), and silicon (0.3 to 3. 1 atomic %) in the range of composition given in parentheses; and that contains the fol lowing elements in the specified range of composition given in parentheses: chromium ( 1 5 to 20 atomic %), molybdenum (2 to 1 5 atomic %), tungsten ( I to 3 atomic %), boron (5 to 1 6 atomic %), carbon (3 to 16 atomic %), and the balance iron.

|00057| The aforedescribed amorphous al loy systems can further include additional elements, such as additional transition metal elements, including Nb, Cr, V, and Co. The additional elements can be present at less than or equal to about 30 wt%, such as less than or equal to about 20 wt%, such as less than or equal to about 10 wt%, such as less than or equal to about 5 wt%. In one embodiment, the additional, optional element is at least one of cobalt, manganese, zirconium, tantalum, niobium, tungsten, yttrium, titanium, vanadium and hafnium to form carbides and further improve wear and corrosion resistance. Further optional elements may include phosphorous, germanium and arsenic, totaling up to about 2%, and preferably less than 1 %, to reduce melting point. Otherwise incidental impurities should be less than about 2% and preferably 0.5%.

Table 1. Exemplary amorphous alloy compositions

|00058| In some embodiments, a composition having an amorphous alloy can inc lude a small amount of impurities. The impurity elements can be intentionally added to modify the properties of the composition, such as improving the mechanical properties (e.g., hardness, strength, fracture mechanism, etc.) and/or improving the corrosion resistance. Alternatively, the impurities can be present as inevitable, incidental impurities, such as those obtained as a byproduct of processing and manufacturing. The impurities can be less than or equal to about 10 wt%, such as about 5 wt%, such as about 2 wt%, such as about I wt%, such as about 0.5 wt%, such as about 0. 1 wt%. In some embodiments, these percentages can be volume percentages instead of weight percentages. In one embodiment, the alloy

sample/composition consists essentially of the amorphous alloy (with only a small incidental amount of impurities). In another embodiment, the composition includes the amorphous alloy (with no observable trace of impurities).

[00059| In one embodiment, the final parts exceeded the critical casting thickness of the bulk solidi fying amorphous alloys.

[00060) In embodiments herein, the existence of a supercooled liquid region in which the bulk-solidifying amorphous alloy can exist as a high viscous liquid allows for superplastic forming. Large plastic deformations can be obtained. The ability to undergo large plastic deformation in the supercooled liquid region is used for the forming and/or cutting process. As oppose to solids, the liquid bulk solidifying alloy deforms locally which drastically lowers the required energy for cutting and forming. The ease of cutting and forming depends on the temperature of the al loy, the mold, and the cutting tool . As higher is the temperature, the lower is the viscosity, and consequently easier is the cutting and forming.

|00061 ] Embodiments herein can utilize a thermoplastic-forming process with amorphous alloys carried out between Tg and Tx, for example. Herein, Tx and Tg are determined from standard DSC measurements at typical heating rates (e.g. 20 °C/min) as the onset of crystallization temperature and the onset of glass transition temperature.

(00062 ) The amorphous alloy components can have the critical casting thickness and the final part can have thickness that is thicker than the critical casting thickness. Moreover, the time and temperature of the heating and shapi ng operation is selected such that the elastic strain limit of the amorphous alloy could be substantially preserved to be not less than 1 .0 %, and preferably not being less than 1 .5 %. In the context of the embodiments herein, temperatures around glass transition means the forming temperatures can be below glass transition, at or around glass transition, and above glass transition temperature, but preferably at temperatures below the crystallization temperature T_x . The cooling step is carried out at rates similar to the heating rates at the heating step, and preferably at rates greater than the heating rates at the heating step. The cool ing step is also achieved preferably while the forming and shaping loads are still maintained.

Electronic Devices

(00063) The embodiments herein can be valuable in the fabrication of electronic devices using a BMG. An electronic device herein can refer to any electronic device known in the art. For example, it can be a telephone, such as a cell phone, and a land-line phone, or any communication device, such as a smart phone, including, for example an iPhone™, and an electronic email sending/receiving device. It can be a part of a display, such as a digital display, a TV monitor, an electronic-book reader, a portable web-browser (e.g. , iPad™), and a computer monitor. It can also be an entertainment device, including a portable DVD player, conventional DVD player, Blu-Ray disk player, video game console, music player, such as a portable music player (e.g. , iPod™), etc. It can also be a part of a device that provides control, such as controlling the streaming of images, videos, sounds (e. g. , Apple TV™), or it can be a remote control for an electronic device. It can be a part of a computer or its accessories, such as the hard drive tower housing or casing, laptop housing, laptop keyboard, laptop track pad, desktop keyboard, mouse, and speaker. The article can also be applied to a device such as a watch or a clock.

[00064] The methods, techniques, and devices illustrated herein are not intended to be limited to the i llustrated embodiments.

[00065] As disclosed herein, a system (or a device or a machine) is configured to perform injection molding of material(s) (such as amorphous alloys). The system is configured to process such materials or alloys by melting at higher melting temperatures before injecting the molten material into a mold for molding. As further described below, parts of the system are positioned i n-line with each other. In accordance with some embodiments, parts of the system (or access thereto) are aligned on a horizontal ax is.

100066] FIG. 3 il lustrates a schematic diagram of such an exemplary system. Although the system illustrated in the Figures is a system al igned along a horizontal ax is, it should be understood and within the scope of this disclosure that similar features may be provided on a vertically positioned injection molding system (e.g. , wherein there is vertical movement of material into a mold), and that herein disclosed features can be applied to a vertical system.

100067) As shown, horizontal injection molding system 10 has a melt zone 1 2 configured to melt meltable material received therein, and a dual plunger rod assembly configured to transport molten material from the melt zone 1 2 and into a mold 16. The dual plunger rod assembly includes a first plunger rod 14 and a second plunger rod 22. At least the first plunger rod 14 is configured to move, transport, transfer and/or eject molten material from melt zone 12 and into a mold 16. In an embodiment, the first and second plunger rods 14 and 22 are configured to transport molten material from melt zone 1 2 and into mold 16. The first plunger rod 14 and the second plunger rod 22 are configured to move along a same axis. Among other things, the first and second plungers rods are configured to contain molten material (e.g., melted in melt zone 12) therebetween during movement of the molten material into mold 1 6. The first plunger rod 14 and the second plunger rod 22 have movable rods with plunger tips 24 and 36, respectively, that are configured to contact and transport material. Further description regarding features of the dual plunger rod assembly is detailed below with reference to FIGS. 4-8. In one embodiment, the dual plunger rod assembly and melt zone 12 are provided in-l ine and on a horizontal axis (e.g., X axis), such that plunger rods 14 and 22 are moved in a horizontal direction (e.g. , along the X-axis).

(00068) The meltable material can be received in the melt zone in any number of forms. For example, the meltable material may be provided into melt zone 12 in the form of an ingot (solid state), a semi-solid state, a slurry that is preheated, powder, pellets, etc. In some embodiments, a loading port (such as the il lustrated example of an ingot loading port 1 8) may be provided as part of injection molding system 10. Loading port 1 8 can be a separate opening or area that is provided within the machine at any number of places. In an embodiment, loading port 1 8 may be a pathway through one or more parts of the machine. For example, the material (e.g., ingot) may be inserted in a horizontal direction into vessel 20 by plunger 14, or may be inserted in a horizontal direction from the mold side of the injection system 10 by plunger 22 (e.g. , through mold 16 and/or through an optional transfer sleeve 30 and into vessel 20). In other embodiments, the meltable material can be provided into melt zone 12 in other manners and/or using other devices (e.g., through an opposite end of the injection system). |00069) Melt zone 12 inc ludes a melting mechanism configured to receive meltable material and to hold the material as it is heated to a molten state. The melting mechanism may be in the form of a vessel 20, for example, that has a body for receiving meltable material and configured to me lt the material therein. A vessel as used throughout this disclosure is a container made of a material employed for heating substances to high temperatures. For example, in an embodiment, the vessel may be a crucible, such as a boat style crucible, or a skull crucible. In an embodiment, vessel 20 is a cold hearth melting device that is configured to be utilized for meltable material(s) whi le under a vacuum (e.g. , applied by a vacuum device 38 or pump). In one embodiment, the vessel is a temperature regulated vessel .

[00070| Vessel 20 may have an inlet for inputting material (e.g. , feedstock) into a recei ving or melting portion of its body. Vessel 20 can comprise any number of shapes or configurations. Vessel 20 may receive material (e.g. , in the form of an ingot) in its melting portion using one or more devices of an injection system for delivery (e.g. , loading port and/or plunger(s)). The body of the vessel has a length and can extend in a longitudinal and horizontal direction, such that molten material is removed horizontally therefrom using plunger 1 4 and/or plunger 22. Its body may be formed from any number of materials (e.g. , copper, silver), include one or more coatings, and/or configurations or designs. The body of vessel 20 may be configured to receive at least plunger rod 1 therei n and therethrough in a horizontal direction to move the molten material. In an embodiment, both first plunger rod 14 and second plunger rod 22 and/or at least their tips 24 and 36, respectively, are configured to be positioned in or adjacent the body of the vessel (e.g., when melting material). That is, in an embodiment, the melting mechanism is on the same axis as the plunger rods 14 and 22, and the body can be configured and/or sized to receive at least part of the plunger rods 14 and 22. Thus, at least plunger rod 14 can be configured to move molten material (after heating/melting) from the vessel by moving substantially through vessel 20, and into mold 16 (e.g. , as shown and described with reference to FIGS. 5-6).

100071 ) To heat melt zone 1 2 and melt the meltable material received in vessel 20, injection system 10 includes a heat source that is used to heat and melt the meltable material. At least a melting portion of the vessel , if not substantially the entire body itself, is configured to be heated such that the material received therein is melted. Heating is accomplished using, for example, an induction source 26 positioned within melt zone 12 that is configured to melt the meltable material. In an embodiment, induction source 26 is positioned adjacent vessel 20. For example, induction source 26 may be in the form of a coil positioned in a helical pattern substantial ly around a length of the vessel body. Accordingly, vessel 20 is configured to inductively melt a meltable material (e.g. , an inserted ingot) within its melting portion by supplying power to induction source/coil 26, using a power supply or source 28. Induction coil 26 is configured to heat up and melt any material that is contained by vessel 20 without melting and wetting vessel 20. Induction coil 26 emits radiofrequency (RF) waves towards vessel 20. As shown, coi l 26 surrounding vessel 20 may be configured to be positioned in a horizontal direction along a horizontal axis (e.g. , X axis).

[00072] In one embodiment, the vessel 20 is a temperature regulated vessel. Such a vessel may inc lude one or more temperature regulating lines configured to flow a liquid (e.g. , water, or other fluid) therein for regulating a temperature of the material received in the vessel (e.g., to force cool the vessel). Such a forced-cool crucible can also be provided on the same axis as the plunger rod. The cooling line(s) assist in preventing excessive heating and melting of the body of the vessel 20 itself. In an embodiment, either or both first and second plunger rods 14 and 22 may include temperature regulating lines. For example, lines may be provided in each of the rods and into tips 24 and 36 of the plunger rods 14 and 22 (not shown). Such an addition of cooling liquid may assist in keeping plunger tips 24 and 36 cool while transporting material, preventing excessive heating and/or melting of the tips, for example. In an embodiment, both of the plunger rods are water cooled (or forced cooled) to act as a quenching mechanism. In one embodiment, both plungers may be provided at or cooled to a similar temperature. In another embodiment, one plunger (and/or its tip) may have a higher temperature than the other plunger (and/or its tip). In another embodiment, one plunger (and/or its tip) may be at a temperature higher than Tg of the material/al loy. In yet another embodiment, one plunger may be at a temperature within the super cooled region of the casting alloy.

[00073) Any of the herein cooling line(s) may be connected to a cooling system (not shown) configured to induce flow of a liquid in the vessel. The cooling line(s) may include one or more inlets and outlets for the liquid or fluid to flow therethrough. The inlets and outlets of the cooling lines may be configured in any number of ways and are not meant to be limited. The number, positioning and/or direction of the cooling line(s) should not be limited. The cooli ng l iquid or fluid may be configured to flow through the cooling line(s) during melting of the meltable material in the melt zone 12, when induction source 26 is powered, and/or during transport of the molten material from the melt zone 12.

|00074) As previously noted, systems such as injection molding system 10 that are used to mold materials such as metals or al loys may implement a vacuum when forcing molten material into a mold or die cavity. Injection molding system 10 can further includes at least one vacuum source 38 or pump that is configured to apply vacuum pressure to at least melt zone 1 2 and mold 16. The vacuum pressure may be applied to at least the parts of the injection molding system 10 used to melt, move or transfer, and mold the material therein. For example, the vessel 20, a transfer sleeve 30 (described below), and dual plunger rod assembly may all be under vacuum pressure and/or enclosed in a vacuum chamber during the melting and injection process.

(000751 In an embodiment, mold 1 6 is a vacuum mold that is an enclosed structure configured to regulate vacuum pressure therein when molding materials. For example, as shown in FIGS. 6-8, in an embodiment, vacuum mold 16 has a first mold plate 32 (also referred to as an "A" mold or "A" plate) and a second mold plate 34 (also referred to as a "B" mold or "B" plate) positioned adjacently (respectively) with respect to each other. First plate 32 and second plate 34 each have a mold cavity 42 and 44, respectively, associated therewith for molding melted material therebetween. As shown in the representative cross-sectional view of FIG . 7, the cavities 42 and 44 are configured to mold molten material received therebetween via a transfer sleeve 30. Mold cavities 42 and 44 may include a part cavity for forming and molding a part therein.

(00076) Generally, first plate 32 may be connected to transfer sleeve 30. Transfer sleeve 30 (sometimes referred to as a cold sleeve or injection sleeve in the art) may be provided between melt zone 1 2 and mold 16. Transfer sleeve 30 has an opening that is configured to receive and allow transfer of the molten material therethrough and into mold 16 (using plunger 14). Its opening may be provided in a horizontal direction along the horizontal ax is (e.g. , X axis). The transfer sleeve need not be a cold chamber. In an embodiment, plunger rods 14 and 22, vessel 20 (e.g. , its recei ving or melting portion), and opening of the transfer sleeve 30 are provided in-line and on a horizontal axis, such that plunger rod 14 and/or plunger rod 22 can be moved in a horizontal direction through vessel 20 in order to move the molten material into (and subsequently through) the opening of transfer sleeve 30.

100077) First plate 32 can include the inlet of the mold 1 6 such that molten material can be inserted therein. Molten material is pushed in a horizontal direction through transfer sleeve 30 and into the mold cavity(ies) via the inlet between the first and second plates, 32 and 34. During molding of the material, the at least first and second plates 32 and 34 are configured to substantially eliminate exposure of the material (e.g., amorphous alloy) therebetween to at least oxygen and nitrogen. Specifically, a vacuum is applied such that atmospheric air is substantial ly el iminated from within the plates 32 and 34 and their cavities 42 and 44. A vacuum pressure is applied to an inside of vacuum mold 1 6 using at least one vacuum source 38 that is connected via vacuum lines. For example, the vacuum pressure or level on the system can be held between 1 x 10^"' to 1 x 10^"* Torr during the melting and subsequent molding cyc le. In another embodiment, the vacuum level is maintained between l x l O^'2 to about I x l O Torr during the melting and molding process. Of course, other pressure levels or ranges may be used, such as l x l O^'9 Torr to about l x l O^"3 Torr, and/or l x l O^'3 Torr to about 0. 1 Torr.

|00078| Although not shown, an ejector mechanism may be optionally provided to eject molded (amorphous al loy) material (e.g., an object) from the mold cavity between the at least first and second plates 32 and 34. Ejector mechanism can be vacuum sealed relative to the mold and may include an ejector plate with one or more (multiple) ejector pins (not shown) extending in a linear direction therefrom. As generally known in the art, upon movement of an ejector plate, the ejector pins are moved relatively to eject the molded material from the mold cavity of mold 16. The ejection mechanism may be associated with or connected to an actuation mechanism (not shown) that is configured to be actuated in order to eject the molded material or part (e.g., after first and second parts 32 and 34 are moved horizontally and relatively away from each other, after vacuum pressure between the plates 32 and 34 is released). The ejector pins may be configured to push molded material away from cavity 44, for example. In an embodiment, as further described below with reference to FIG. 8, second plunger rod 22 of dual plunger assembly is configured to eject a molded object from mold 16. Second plunger rod 22 may be provided to eject a molded object in addition to or in place of an ejection mechanism. (00079) The illustrated mold 16 is one example of a mold 16 that can be used with injection molding system 10. It should be understood that alternate types of molds may also be employed. For example, any number of additional plates may be provided between and/or adjacent the first and second plates to form the mold. Molds known as "A" series, "B" series, and/or "X" series molds, for example, may be implemented in injection molding system 10. Moreover, in an embodiment, a single plate type mold can be used to mold an object.

|00080| Referring back to FIG. 3 , the first plunger rod 14 and the second plunger rod 22 of the dual plunger rod assembly are configured to move horizontally along a horizontal axis. For example, as shown by arrow A, first plunger rod 14 is configured to move towards (and through) melt zone 1 2 , and back in an opposite direction. As shown by arrow B, second plunger rod 22 is configured to move towards (and at least adjacent or into) melt zone 1 2 , and back in an opposite direction. Again, each of first plunger rod 24 and second plunger rod 22 can have movable rods (e.g. , bases) with plunger tips 24 and 36, respecti vely, at an end thereof. In an embodiment, the tips 24 and/or 36 of the rods 14 and 22 are configured to transport material. At least the first plunger rod 14 is configured to move molten material towards mold 16. As previously noted, in an embodiment, the first plunger rod 14 and the second plunger rod 22 may be configured to move relative to each other to move molten material from melt zone 1 2 and into mold 16. Each of the rods may be controlled and moved using a controller and/or an actuation system (e.g. , servo-driven drive or a hydraulic drive, not shown) independently and/or jointly. Also, the speed, pressure, or other metrics applied to the material during the process should not be limited. For example, in an embodiment, first and second plunger rods 14 and 22 are configured to apply a pressure between approximately 1000 bar to approximately 1400 bar to the molten material during the molding process. In another embodiment, the applied pressure (on either or both sides of the material) is approximately 1200 bar.

(000811 To do so, as shown in FIG. 4, first plunger rod 14 is moved along the horizontal axis towards vessel 20 in melt zone 1 2, as represented by arrow C. Similarly, second plunger rod 22 is moved along the horizontal ax is towards vessel 20 in me lt zone 12, as represented by arrow D. In an embodi ment, at least a portion (e.g. , tip) of each of the plunger rods 1 4 and 22 may be provided adjacent to or within vessel 20, e.g. , to contain a material during melting and in molten form. For example, an ingot may be placed within the body of vessel and the first and second plunger rods may be spaced a distance from each other during the melting process. The distance may be predetermined. The tip 24 of first plunger rod 1 and tip 36 of second plunger rod 22 may be spaced relative to or touching the meltable material (ingot) just before the melting process begins. When induction coi l 26 is powered to melt the ingot of material, the first plunger rod 14 is typically maintained in its position. In an embodiment, because second plunger rod 22 is spaced at a distance from first plunger rod 14 within the melt zone 1 2, the second plunger rod 22 , therefore, acts as a retaining or containment gate during at least the melting process.

[00082 | After the material is melted in the vessel 20, the second plunger rod 22 is configured to move in concert with the first plunger rod 14 to encourage laminar flow of the molten material in a horizonta l direction towards mold 16. The mold can be positioned adjacent to the melt zone. By containing the molten material between the plunger rods 14 and 22 during movement thereof, it reduces rol ling of the molten material (which can reduce mixing of skull material therein) and can assist in maintaining molten material at a higher melt temperature. FIG. 5 illustrates movement of the molten material by first and second plunger rods 14 and 22 towards mold 16, as represented by arrows F and E, respectively. For example, first and second plunger rods 1 4 and 22 would move in a horizontal direction from the right towards the left, from vessel 20 in melt zone 1 2, moving and pushing the molten material towards mold 16. The molten material is moved from the melt zone 1 2/vessel 20 and through optional transfer sleeve 30, while the distance between the tips 24 and 36 is maintained (e.g., to control transport of the molten material as well as prevent any additional air or materials in the space). Accordingly, second plunger rod 22 acts as a molten material retaining gate during part or al l of the injection molding process.

[00083| Once at mold 16, first plunger rod 14 may be used to force the molten material into a mold 16 for molding into an object, a pan or a piece. In instances wherein the meltable material is an alloy, such as an amorphous al loy, the mold 16 is configured to form a molded bulk amorphous alloy object, part, or piece. Mold 16 has an inlet for receiving molten material therethrough. An output of the vessel 20 and an inlet of the mold 16 can be provided in-line and on a horizontal axis such that plunger rods 14 and 22 are moved in a horizontal direction from the vessel 20 to inject molten material into the mold 16 via its inlet.

[00084) The dual plunger rod assembly can be used to increase packing pressure of the molten material into the mold to ease filling mold cavities (e.g. , of a high aspect ratio part) while doing so without increased or extra force being applied by the plunger rods 14 and/or 22. In an embodiment, the first plunger rod 14 is configured to move in one direction towards the mold along an axis and the second plunger rod 22 is configured to move in a second, opposite direction (to that of first plunger rod) along the axis. For example, as shown in FIG. 6, the second plunger rod 22 is positioned relative to mold 1 6 and configured to stop and/or apply pressure to molten material on one side 34 of the mold as the first plunger rod 14 is configured to proceed and/or continue (without pause or stopping) to move in the horizontal direction (see arrow F), to push or inject molten material into the cavity (or joined cavities 42 and 44) of mold 16 on an opposite side 32 such that the material is forced therein. More spec ifically, in one embodiment, the second plunger rod 22 is stopped in a position so that at least its tip 36 is positioned relative to the mold cavity. The second plunger rod 22 can be configured to be maintained in a stopped position such that at least the first plunger rod 14 appl ies pressure to the molten material when injecting into the mold 16. In another embodiment, the second plunger rod 22 is configured to move in a reverse or opposite direction (e.g., from left to right) such that both of the plungers 1 4 and 22 are moving relative to or towards each other to apply pressure to the material . In yet another embodiment, pressure can be selectively applied by the second plunger rod 22 in the reverse or opposite horizontal direction, as needed. Thus the second plunger rod 22 can be used to add more pressure to a fill of the mold cavity, and from either or both sides. This added pressure can, for example, apply more pressure on the molten material so that a part that is thinner than usual can be molded.

(00085] Accordingly, first and second plunger rods 14 and 22 of the dual plunger assembly as described above are configured to at least move molten material from melt zone 12 and into mold 16 while retaining or containing the molten material therebetween and during movement of the molten material in the horizontal direction.

|00086| However, it should be note that the dual plunger assembly may be configured for operation in a di fferent manner. FIG. 7 i llustrates an alternate embodiment that may be implemented in the described injection system 10, wherein at least the first plunger rod 14 is configured to move molten material from vessel 20 and into mold 16 (in a horizontal direction, e.g. , see arrow G). Although the second plunger rod 22 can be used to transport the molten material from the melt zone 1 2, in another embodiment, the second plunger rod 22 may be configured to be moved and placed in position adjacent or in mold 16 before injection of molten material therein by the first plunger rod 14. Accordingly, second plunger rod 22 is provided adjacent a mold cavity (or cavities) within mold 16 and used to increase packing pressure without extra force and to ease filling of a high aspect ratio cavity, such as described in more detail above with reference to FIG. 6, but second plunger rod 22 need not necessarily be used or limited to continuously transporting molten material from the melt zone 12 towards mold 16.

[00087] In addition to transporting molten material, in an embodiment, either one of the first and second plunger rods 14 and 22 of dual plunger rod assembly may be used as an ejection mechanism to eject a molded object or part from mold 1 6 when the molding process is complete. For example, as indicated by arrows M l and M2 in FIG. 7, first mold plate 32 and second mold plate 34 can move relative to, i.e., towards and away from each other. During molding, for example, plates 32 and 34 are adjacent each other and under vacuum pressure. Once molding is complete, vacuum pressure is released and the molded object can be removed or ejected from the mold. Typically, for example, an ejection mechanism (e.g. , ejection plate and or ejection pins) can be used to eject the molded part, e.g. , from second side 34 of the mold. In accordance with an embodiment illustrated in FIG . 8, the second plunger rod 22 is configured to move in a horizontal direction (e.g. , from left to right, as indicated by arrow H) to eject a molded object 100 from second mold plate 34. At least its tip 36 is used to apply pressure to the molded object 100 so that it is removed from within the mold 16. The second plunger rod 22 (or first plunger rod 14) can be used in addition to an ejection mechanism or as an alternative option to an ejection mechanism. The first plunger rod 14 may be provided in a stationary position relative to the mold 16.

|00088| Alternatively, in another embodiment, should the molded object be maintained in the first mold plate 32 when the plates are separated, or should only a single mold be employed for mold 16, the first plunger rod 14 is configured to move in a horizontal direction (e.g. , from right to left) to eject the molded object from first mold plate 32. In some embodiments, the first plunger rod 14 can be used in addition or alternatively to an ejection mechanism.

100089) Generally, the injection molding system 10 may be operated in the following manner: Meltable material (e.g. , amorphous alloy or BMG) is loaded into a feed mechanism (e.g. , loading port 1 8), inserted and received into the melt zone 12 into the vessel 20 (surrounded by the induction coil 26). The injection molding machine "nozzle" stroke or plunger 14 can be used to move the material, as needed, into the melting portion of the vessel 20. The system can be placed under vacuum using vacuum source 38. The first plunger rod 14 and the second plunger rod 26 are moved into melt zone 12 relative to each other and to the material to be melted and spaced at a distance suitable to contain the material. The material is then heated through the induction process by heating induction coi l 26. Once the temperature is achieved and maintained to melt the meltable material , the heating using induction coil 26 can be stopped and the machine will then begin the injection of the molten material from vessel 20, through transfer sleeve 30, and into vacuum mold 16 by moving in a horizontal direction (from right to left) along the horizontal axis. The movement of the molten material is controlled using both plungers 14 and 22 (e.g. , which can be activated using a servo-driven drive or a hydraulic drive). The mold 16 is configured to receive molten material through an inlet and configured to mold the molten material under vacuum. That is, the molten material is injected into a cavity between the at least first and second plates to mold the part in the mold 16. The second plunger rod 22 can be positioned on second side 34 of the mold to maintain pressure within the mold as the first plunger rod 14 continues to move or push molten material into its cavity. Once the mold cavity has begun to fill , vacuum pressure (via the vacuum lines and vacuum source 38) can be held at a given pressure to "pack" the molten material into the remaining void regions within the mold cavity and mold the material. After the molding process (e.g. , approximately 10 to 1 5 seconds), the vacuum pressure applied to the mold 1 6 is released. Mold 1 6 is then opened to relieve pressure and to expose the part to the atmosphere. Second plunger rod 22 (and/or an ejector mechanism) can be actuated in a horizontal and linear direction (e.g. , towards the right) to eject the solidified, molded object from between the at least first and second plates of mold 16. Thereafter, the process can begin again. Mold 16 can then be closed by moving at least the at least first and second plates relative to and towards each other such that the first and second plates are adjacent each other. The melt zone 12 and mold 16 is evacuated via the vacuum source once the plungers 14 and 22 have moved back into a load position and possibly melting position, in order to melt more received meltable material and mold another part.

(00090| Accordingly, the herein disc losed embodiments i llustrate an exemplary injection system that has its melting system in-line with a dual plunger rod assembly configured for movement along a horizontal axis during the melting and molding process. The system and/or i ts parts do not need to be limited to being positioned for movement of material in a horizontal direction, however. The dual plunger rod assembly can be configured to move along any longitudinal axis in a longitudinal direction. For example, in another embodiment, the dual plunger rod assembly and melt zone can be provided along a vertical axis (e.g. , Y-axis, not shown), so that plunger rods 14 and 22 and material are moved from melt zone 1 2 and into mold 16 in a vertical direction.

(00091 ) Accordingly, the dual plunger rod assembly described herein provides a number of employable features to the herein described injection molding system 10. For example, it uses two plungers to retain material therebetween and control transport thereof. Also, with regards to systems provided in line and with at least a melt zone and mold on a horizontal axis, the speed of injection of the molten material into mold 16 can be controlled by the movement of plungers 14 and 22, particularly as compared to pour systems that tend to pour material quickly into a mold, and conventional die casting systems. The disclosed dual plunger system allows for more uniform cooling of the part, and at faster rate than that of a single plunger system.

(00092) Further, because the second plunger rod 22 acts a retention or containment gate (e.g. , during molding), any addition of another gate is unnecessary. This reduces the length and amount of space that may be needed in prior or known systems. Moreover, this can also reduce the length of the transfer sleeve 30 (if provided). Accordingly, by having a dual plunger adjacent sleeves such as transfer sleeve 30 and/or other parts in the machine can be shortened, which in turn allows for the molten material to be pushed more quickly into the mold by shortening the distance it needs to move from the melt zone before arriving at the mold input. It also means that the molten material wil l arrive at the mold at a higher temperature, and that during molding the material is less subject to defects based on the quenching rate of the mold. In particular, when using materials that go amorphous, maintaining a higher temperature and reducing the rate at which such molten material cools as it travels towards the mold improves its glass formability (before quenching quickly in the mold). By keeping the molten material contained in a space or distance between the two plunger rods 14 and 22 as they move in concert towards the mold, the surface area can be can kept relatively the same, as well as the temperature. |00093| Moreover, using the dual plunger rod assembly may aid in reducing surface defects in molded objects by forcing a more laminar flow of material. Typically, when molten material is able to roll, at least some of the skull material (e.g. , from the bottom) may end up within the molten material. Thus, some unwanted crystallized material can be molded and end up in the final part. However, if molten material is moved in a relatively linear manner, as provided by the plungers 14 and 22, rolling of skull material into the melt can be reduced and/or avoided. The dual plunger rod assembly disclosed herein can also reduce defects by filling smaller features in the molds by keep pressure on the melt at all times, and filling larger parts by allowing for an increase in the velocity of the flow (since it is controlled by both plungers). It also traps and/or prevents air or porosity within the distance or space between the two plungers.

[00094| In addition to the features described herein, it should be understood that the dimensions and materials used for the plunger rods 14 and 22 should not be limited. Any number of materials can be used to form the rods and/or the tips 24 and 36 thereof. Different materials may be used to form different parts. The tips 24 and 36 may be formed of one or more materials. In an embodiment, at least the tips of both plunger rods 14 and 22 have a similar diameter. In another embodiment, plunger rod 14 and plunger rod 22 have different diameters. In another embodiment, one or more of the rods 14 and/or 22 may include a telescopic body. In yet another embodiment, one plunger may contain another plunger therein.

|00095) Although not described in great detail, the disclosed injection system may include additional parts inc luding, but not limited to, one or more sensors, flow meters, etc. (e.g. , to monitor temperature, cooling water flow, etc.), and/or one or more controllers. Also, seals can be provided with or adjacent any of number of the parts to assist during melting and formation of a part of the molten material when under vacuum pressure, by substantially limiting or eliminating substantial exposure or leakage of air. For example, the seals may be in the form of an O-ring. A seal is defined as a device that can be made of any material and that stops movement of material (such as air) between parts which it seals. The injection system may implement an automatic or semi -automatic process for inserting meltable material therein, applying a vacuum, heating, injecting, and molding the material to form a part. 100096) The material to be molded (and/or melted) using any of the embodiments of the injection system as disclosed herein may include any number of materials and should not be limited. In one embodiment, the material to be molded is an amorphous alloy, as described in detail above.

(00097) While the principles of the disclosure have been made clear in the illustrative embodiments set forth above, it will be apparent to those ski lled in the art that various modifications may be made to the structure, arrangement, proportion, elements, materials, and components used in the practice of the disclosure.

|00098| It wil l be appreciated that many of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other di fferent systems/devices or applications. Various presently unforeseen or unantic ipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.

Claims

WHAT IS CLAIMED IS :

1 . An injection molding system comprising :

a melt zone configured to melt meltable material received therein, and

a dual plunger rod assemblv comprising a first plunger rod and a second plunger rod, at least the first plunger rod being configured to move molten material from the melt zone and into a mold, the dual plunger rod assemblv and the melt zone being provided in-line, and the first and second plunger rods configured to move along a longitudinal axis , such that at least the first plunger rod is moved in a longitudinal direction from the melt zone to move the molten material into the mold.

2. The system according to claim 1 , w herein the mold is provided in-line w ith the dual plunger rod assemblv and the melt zone so as to receive the molten material therein.

3. The system according to claim 1 , w herein the melt zone comprises a vessel having a body for receiving the meltable material, the body configured to receive at least the first plunger rod therethrough in the longitudinal direction to move the molten material into the mold.

4. The system according to claim 1 , w herein the second plunger rod is configured to move molten material in a longitudinal direction from the melt zone to move the molten material into the mold.

5. The system according to claim 3 , w herein the first plunger rod and the second plunger rod are provided adjacent to the meltable material in the melt zone and w herein the first and second plunger rods are configured to contain the molten material therebetw een during longitudinal movement of the molten material tow aids the mold.

6. The system according to claim 1 , w herein the second plunger rod is configured to be positioned relative to the mold and configured to apply pressure to molten material on one side of the mold as the first plunger rod is configured to move in the longitudinal direction to push molten material into the mold on an opposite side of the mold such that the molten material is forced into a cavity of the mold.

7. The system according to claim 1 , w herein the second plunger rod is configured to eject a molded object from the mold.

8. The sy stem according to claim 1 , w herein the movement of each of the first plunger rod and the second plunger rod along the longitudinal axis is independently controlled via at least one controller.

9. The system according to claim 1 , w herein the longitudinal axis is a horizontal axis, and w herein the first and second plunger rods are configured to move in a horizontal direction.

10. The system according to claim 1 , further comprising an induction source positioned within the melt zone that is configured to melt the meltable material.

1 1. The system according to claim 1 , further comprising a transfer sleeve betw een the melt zone and the mold configured to receive the molten material therethrough.

12. The system according to claim 2 , further comprising at least one vacuum source that is configured to apply vacuum pressure to at least the melt zone and the mold.

13. The system according to claim 1 , w herein the meltable material is an alloy and w herein the mold is configured to form a molded bulk amorphous alloy object.

14. An injection molding system comprising :

a melt zone configured to melt meltable material received therein,

a mold configured to receive molten material therein for molding, and

a first plunger rod and a second plunger rod configured to move relative to each other, the first plunger rod and the second plunger rod being configured to move the molten material from the melt zone and into the mold.

15. The system according to claim 14, w herein the fust plunger rod and the second plunger rod configured to be provided adjacent to the meltable material in the melt zone during melting and configured to contain the molten material therebetw een during movement of the molten material tow ards the mold.

16. The system according to claim 15, w herein the fust plunger rod and the second plunger rod are spaced a distance from each other during melting of the meltable material, and w herein the distance is maintained during movement of the molten material.

1 7. The system according to claim 14, w herein the fust plunger rod and the second plunger rod are configured to move along a same axis.

18. The system according to claim 14, w herein the fust plunger rod is configured to move in one direction tow aids the mold along an axis and w herein the second plunger rod is configured to move in a second opposite direction along the axis.

19. The system according to claim 18, w herein the fust plunger rod and the second plunger rod are configured to move along a longitudinal axis.

20. The system according to claim 14, w herein the fust plunger rod and the second plunger rod are configured to move along a longitudinal axis.

2 1. The system according to claim 19, w herein the longitudinal axis is a horizontal axis.

22. The system according to claim 20, w herein the longitudinal axis is a horizontal axis.

23. The system according to claim 14, w herein the melt zone comprises a vessel having a body for receiving the meltable material, the body configured to receive at least the first plunger rod therethrough to move the molten material into the mold.

24. The system according to claim 14, w herein the second plunger rod is configured to be positioned relative to the mold and configured to apply pressure to molten material on one side of the mold as the first plunger rod is configured to move the molten material into the mold on an opposite side of the mold such that the molten material is forced into a cavity of the mold.

25. The system according to claim 14, w herein the second plunger rod is configured to eject a molded object from the mold.

26. The sy stem according to claim 14, w herein the movement of each of the first plunger rod and the second plunger rod is independently controlled via at least one controller.

27. The system according to claim 14, further comprising at least one vacuum source that is configured to apply vacuum pressure to at least the melt zone and the mold.

28. The system according to claim 14, w herein the meltable material is an alloy and w herein the mold is configured to form a molded bulk amorphous alloy object.

29. A method of molding an object from meltable material using an injection molding system, the system comprising a melt zone configured to melt the meltable material received therein and a plunger rod assemblv comprising a first plunger rod and a second plunger rod, the assemblv configured to move molten material from the melt zone and into a mold, the method comprising :

melting a meltable material in the melt zone , and

moving the molten material from the melt zone and into the mold. w herein the first plunger rod and the second plunger rod are configured to contain the molten material therebetw een during movement of the molten material tow ards the mold.

30. The method of claim 29, w herein the first plunger rod and the second plunger rod are moved along a longitudinal axis and w herein the moving of the molten material from the melt zone and into the move is in a longitudinal direction.

3 1. The method of claim 29, w herein the first plunger rod and the second plunger rod are moved along a horizontal axis and w herein the moving of the molten material from the melt zone and into the move is in a horizontal direction.

32. The method according to claim 29, w herein the meltable material is an alloy and w herein the mold is configured to form a molded bulk amorphous alloy object.

33. The method according to claim 29, further comprising molding the molten material and, after molding, using the second plunger rod to eject the object from the mold.