US20040004107A1 - Method and apparatus for producing a refined grain structure - Google Patents
Method and apparatus for producing a refined grain structure Download PDFInfo
- Publication number
- US20040004107A1 US20040004107A1 US10/609,951 US60995103A US2004004107A1 US 20040004107 A1 US20040004107 A1 US 20040004107A1 US 60995103 A US60995103 A US 60995103A US 2004004107 A1 US2004004107 A1 US 2004004107A1
- Authority
- US
- United States
- Prior art keywords
- preform
- workpiece
- die
- pins
- process according
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K20/00—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
- B23K20/12—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating the heat being generated by friction; Friction welding
- B23K20/122—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating the heat being generated by friction; Friction welding using a non-consumable tool, e.g. friction stir welding
- B23K20/1275—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating the heat being generated by friction; Friction welding using a non-consumable tool, e.g. friction stir welding involving metallurgical change
Abstract
Description
- This application is a divisional of U.S. application Ser. No. 10/145,009, filed May 14, 2002, which is hereby incorporated herein in its entirety by reference.
- The present invention relates to the grain structure of workpieces formed from metals and metal alloys and, more particularly, relates to an apparatus and an associated method for producing a refined grain structure in a workpiece.
- Structural assemblies, such as those in the aerospace industry, are often constructed by joining structural members together. During use, these structural assemblies can be subjected to a variety of environmental conditions, temperature variations, load variations, severe acoustic and vibration environments, all of which create mechanical and thermal stresses. The reliability and performance of the structural assemblies under these stresses depends in large part on the material properties of the constituent structural members and any weld joints between the members.
- It is commonly recognized that the grain structure of structural members can have an adverse effect on the material properties of the structural members and any weld joints between the members. For example, the grain structure typically associated with conventional aluminum mill products can limit the formability, toughness, weldability, corrosion resistance and strength of structural members formed from these products. As an indication of formability, the typical elongation of AA 2195 aluminum alloys in the T8A3 condition along the longitudinal axis is approximately 11%. The typical elongation of AA 2219 aluminum alloys in the T87 condition along the longitudinal axis is approximately 10%. It is generally believed that the low formability of conventional aluminum mill products, especially in the AA 2195 aluminum alloys, is due to directionality of the grains and poor interlaminar strength. In addition, conventional aluminum mill products joined using common fusion welding techniques typically exhibit weld cracking in the heat affected zone, which can result in relatively weak weld joints. It is generally believed that the poor weldability of conventional aluminum mill products is a result of constitutional liquidation along the grain boundaries as the products are welded.
- In addition too conventional aluminum wrought products, metal matrix composites have been implemented in the aerospace industry where high specific strength is required. Metal matrix composites are typically fabricated using powder metallurgy. Powder metallurgy products consist of fine metal powder and ceramic particles compressed together under controlled temperature and pressure (sintering) to produce a billet of material. The high expense associated with the production of fine metal powder and the sintering process makes these powder metallurgy billets less affordable.
- In seeking to improve the material properties of structural members constructed of metals and metal alloys, it has been proposed to refine the grain size of the structural members through a process known as “equal angle extrusion.” As illustrated in FIG. 1, equal angle extrusion involves forcing a
workpiece 10, using pneumatic or hydraulic pressure, through a die 12 have a 90° bend. In theory, equal angle extrusion crushes the existing grain structure of theworkpiece 10 such that the resulting material exiting the extrusion die 12 will exhibit a reduction in grain size. However, difficulties associated with large loads on thedie 12 and cracking of theworkpiece 10, can adversely affect the properties of the material existing the die. As a result, equal angle extrusion has not been used in large-scale production. - Thus, there remains a need for an apparatus for refining the grain structure of workpieces to thereby provide structural members having improved material properties, such as formability, weldability, toughness, corrosion resistance, and strength. The apparatus should be capable of operating on workpieces that are formed of a variety of metals and metal alloys and that have a variety of configurations. The apparatus also should be cost effective and should be scalable for use in large-scale production operations.
- The present invention provides an apparatus and associated method for operating on a workpiece. According to one embodiment of the present invention, the apparatus comprises a die defining first and second apertures and an interior therebetween. The first aperture and the interior of the die are structured to receive the workpiece. The apparatus includes at least one rotatable pin extending at least partially into the interior of the die. In one embodiment, the die has first and second sides at least partially defining the interior and wherein the pin extends from the first side to the second side so as to traverse the interior of the die. The pin is structured to at least partially stir the workpiece as the workpiece moves through the interior of the die to thereby refine the grain structure of the workpiece. In one embodiment, the apparatus includes a ram structured to urge the workpiece through the interior of the die from the first aperture to the second aperture.
- The interior of the die can be structured to shape the workpiece into a predetermined configuration, such as a square, a rectangle or a cylinder, to thereby cost effectively combine the operations of shaping the workpiece and refining the grain structure of the workpiece. In another embodiment, the interior of the die defines a chamber adjacent the second aperture that is structured to consolidate the workpiece. The rotatable pin can extend into the interior of the die between the first aperture and the chamber.
- The apparatus can include a plurality of rotatable pins extending at least partially into the interior. Each of the pins is structured to stir the workpiece as the workpiece moves through the interior of the die. In another embodiment, the apparatus comprises a rotatable turret to which the plurality of pins are rotatably mounted. The turret is structured to individually rotate each of the pins in corresponding first directions and to collectively rotate the pins in a second direction. In one embodiment, the corresponding first directions are the same as the second direction. In another embodiment, the corresponding first directions are opposite to the second direction. In still another embodiment, the corresponding first directions comprise rotating at least two of the pins in opposite directions.
- According to another embodiment of the present invention, the apparatus comprises at least one motor having a rotatable spindle. The apparatus includes a die defining first and second apertures and an interior extending therebetween, wherein the interior of the die is structured to form the workpiece. For example, in one embodiment, the interior of the die is structured to shape the workpiece into a predetermined configuration, such as a square, a rectangle or a cylinder. The apparatus includes at least one pin in rotatable communication with the spindle. The pin extends at least partially into the interior of the die and is structured to at least partially mix the workpiece as the workpiece moves through the interior to thereby refine the grain structure of the workpiece. In one embodiment, the die has first and second sides at least partially defining the interior and wherein the pin extends from the first side to the second side so as to traverse the interior of the die. The apparatus can include a ram structured to urge the workpiece through the interior of the die from the first aperture to the second aperture.
- In another embodiment, the apparatus comprises a rotatable turret that is in rotatable communication with the spindle of the motor. The apparatus includes a plurality of pins each being in rotatable communication with the turret. Each of the pins extends from the turret at least partially into the interior of the die. The turret is structured to individually rotate each of the pins in corresponding first directions and to collectively rotate the pins in a second direction. The pins are structured to at least partially mix the workpiece as the workpiece moves through the interior of the die to thereby refine the grain structure of the workpiece. In one embodiment, the corresponding first directions are the same as the second direction. In another embodiment, the corresponding first directions are opposite to the second direction. In still another embodiment, the corresponding first directions comprise rotating at least two of the pins in opposite directions.
- In another embodiment, the apparatus comprises a plurality of motors each having a rotatable spindle. The apparatus includes a plurality of pins each being in rotatable communication with a corresponding one of the spindles. Each of the pins extends at least partially into the interior of the die. The pins are structured to at least partially mix the workpiece as the workpiece moves through the interior of the die to thereby refine the grain structure of the workpiece.
- The present invention also provides a method of operating on a workpiece. According to one embodiment, the method includes moving a workpiece through a die. Concurrently with the moving step, the workpiece is mixed with at least one rotating pin to thereby refine the grain structure of the workpiece. In one embodiment, the workpiece is heated concurrently with the mixing step. In another embodiment, the pin and/or die are heated concurrently with the mixing step. For example, the heating step can comprise heating the pin and/or die to a temperature between about 600° F. and about 1000° F. In another embodiment, the die is cooled concurrently with the mixing step. In yet another embodiment, the mixing step comprises individually rotating a plurality of pins in corresponding first directions and collectively rotating the plurality of pins in a second direction. In one embodiment, the corresponding first directions are the same as the second direction. In another embodiment, the corresponding first directions are opposite to the second direction. In still another embodiment, the corresponding first directions comprise rotating at least two of the pins in opposite directions.
- The material properties of the workpiece can be further developed through selective heat treating. In one embodiment, the workpiece is solution heat treated prior to the moving step. In another embodiment, the workpiece is solution heat treated at a predetermined temperature schedule after the mixing step. In yet another embodiment, the workpiece is precipitation heat treated by aging at a second predetermined temperature schedule after the solution heat treating step.
- The present invention also provides a preform for use in forming structural members and assemblies. According to one embodiment of the present invention, the preform comprises a body having predetermined dimensions and wherein the body comprises a refined grain structure having a cross-section comprising a curvilinear configuration. In one embodiment, the grain structure of the body comprises grains having equiaxed shape. In another embodiment, the grain structure comprises grains having a grain size of about 3 microns to about 5 microns. In another embodiment, the body is formed of aluminum, an aluminum alloy, titanium, a titanium alloy or a steel alloy. In still another embodiment, the body has an elongation of between about 15% and about 35%. In yet another embodiment, the body has an elongation of greater than about 20%.
- Accordingly, there has been provided an apparatus and associated method for refining the grain structure of workpieces. The apparatus is capable of operating on workpieces that are formed of a variety of metals and metal alloys and that have a variety of configurations. In addition, the apparatus can be used in large-scale production to cost effectively combine operations, such as forming or shaping the workpieces, while at the same time refining the grain structure of the workpieces to thereby improve the material properties of the workpieces.
- The foregoing and other advantages and features of the invention, and the manner in which the same are accomplished, will become more readily apparent upon consideration of the following detailed description of the invention taken in conjunction with the accompanying drawings, which illustrate preferred and exemplary embodiments and which are not necessarily drawn to scale, wherein:
- FIG. 1 is a cross-sectional view illustrating a die used for equal angle extrusion, as is known in the art;
- FIG. 2 is a cross-sectional view illustrating an apparatus for operating on a workpiece, according to one embodiment of the present invention;
- FIGS.3A-3D are plan views illustrating exemplary configurations for the first aperture and interior of the die, according to various embodiments of the present invention;
- FIG. 4 is a cross-sectional view illustrating the pin of the apparatus of FIG. 2 along lines4-4 of FIG. 2;
- FIG. 5 is a cross-sectional view illustrating an apparatus for operating on a workpiece, according to another embodiment of the present invention;
- FIG. 6 is a cross-sectional view illustrating the pin of the apparatus of FIG. 5 along lines6-6 of FIG. 5;
- FIG. 7 is a cross-sectional view illustrating an apparatus for operating on a workpiece, according to another embodiment of the present invention;
- FIG. 8 is a cross-sectional view illustrating the pins of an apparatus for operating on a workpiece, according to one embodiment of the present invention;
- FIG. 9 is a schematic illustrating the directions of individual and collective rotation of the pins of an apparatus for operating on a workpiece, according to one embodiment of the present invention;
- FIG. 10 is a schematic illustrating the directions of individual and collective rotation of the pins of an apparatus for operating on a workpiece, according to another embodiment of the present invention;
- FIG. 11 is a schematic illustrating the directions of individual and collective rotation of the pins of an apparatus for operating on a workpiece, according to another embodiment of the present invention;
- FIG. 12A is a plan view illustrating an apparatus for operating on a workpiece, according to another embodiment of the present invention;
- FIG. 12B is a sectional view illustrating the apparatus of FIG. 12A along
lines 12B-12B; - FIG. 12C is a sectional view illustrating the apparatus of FIG. 12A along lines12C-12C;
- FIG. 12D is an elevation view illustrating the pin of the apparatus of FIG. 12A;
- FIG. 13A is an elevation view illustrating the first end of an apparatus for operating on a workpiece, according to another embodiment of the present invention;
- FIG. 13B is a sectional view illustrating the apparatus of FIG. 13A along
lines 13B-13B; - FIG. 13C is an elevation view illustrating the pin of the apparatus of FIG. 13A;
- FIG. 14 is an elevation view illustrating an apparatus for operating on a workpiece, according to another embodiment of the present invention;
- FIG. 15 is a perspective view illustrating a rotatable turret, according to one embodiment of the present invention;
- FIG. 16 is a perspective view of a preform, according to one embodiment of the present invention;
- FIG. 17 is a black and white photograph illustrating a cross-section of a preform, according to one embodiment of the present invention;
- FIG. 18A is a hypothetical phase diagram for a precipitation-hardenable binary metal alloy system;
- FIG. 18B is a schematic temperature-versus-time plot showing both solution and precipitation heat treatments for precipitation hardening of the hypothetical binary metal alloy system of FIG. 18A;
- FIG. 18C is a phase diagram for an aluminum-copper metal alloy system; and
- FIG. 19 is a flow chart illustrating a method of operating on a workpiece, according to one embodiment of the present invention.
- The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, this invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.
- Referring now to the drawings, and in particular to FIG. 2, there is illustrated an
apparatus 14 for operating on aworkpiece 22 to thereby form apreform 26, according to one embodiment of the present invention. Theapparatus 14 includes a die 16 defining first andsecond apertures 18 a, b and an interior 20 therebetween. Thefirst aperture 18 a and the interior 20 of the die 16 are structured to receive theworkpiece 22, as indicated by thearrow 24. More specifically, thefirst aperture 18 a and at least a portion of the interior 20 of the die 16 have a configuration generally corresponding to the configuration of theworkpiece 22. For purposes of example only and not limitation, thefirst aperture 18 a and the initial portion of the interior 20 of the die 16 can have a square, rectangular, circular, or elliptical configuration, as illustrated in FIGS. 3A-3D, which generally corresponds to the configuration of theworkpiece 22. - As illustrated in FIG. 2, the
interior 20 of the die 16 also can be structured to shape or form theworkpiece 22 by reducing the cross-sectional area of the workpiece to form apreform 26 having a predetermined configuration, such as a square, a rectangle, a tube, or a cylinder, with pre-selected dimensions. The shaping and forming operations performed by theinterior 20 of the die 16 are similar to the bulk deformation processes associated with extrusion, drawing, or swaging. While structuring the interior 20 of the die 16 to perform the shaping and forming operations is advantageous since it can eliminate the necessity of additional steps in the manufacturing process of thepreform 26, the shaping and forming operations are not required for purposes of the present invention. - The structure and dimensions of the die16 will depend on the configuration and dimensions of the
workpieces 22 and the desired configuration and dimensions of the resultingpreforms 26. The die 16 can be constructed of a variety of materials, including steel alloys, cast iron and nonferrous alloys. The die 16 can be cast, forged or machined from stock material by processes such as milling, turning, grinding, electrical and electrochemical machining, and polishing, as is known in the art. To obtain improved hardness, wear resistance, and strength, the die 16 can be heat treated. Thereafter, the die 16 can be subjected to grinding, polishing, or chemical and electrical machining processes to obtain the desired surface finish and dimensional accuracy. To extend die life, coatings can be applied to thedie 16, as is known in the art. - The
workpiece 22 can be stock material selected based on the desired material properties, configuration and dimensions of the resultingpreform 26. More specifically, theworkpiece 22 can be formed from a variety of materials, as required by the specific design loads, environmental conditions, and specifications of the resulting structural assembly to be formed from thepreform 26. Forpreforms 26 that will be used in aerospace applications, where weight and strength are of critical concern, theworkpiece 22 is preferably formed of aluminum, an aluminum alloy, titanium, a titanium alloy or a steel alloy. If necessary, theworkpiece 22 can be pre-machined using known machining methods so that the workpiece has the desired dimensions and configuration. In addition, theworkpiece 22 can be heat treated, such as by precipitation hardening, or more preferably, by solution heat treating, as discussed more fully below. - According to one embodiment of the present invention, as illustrated in FIGS. 2 and 4, the
apparatus 14 includes arotatable pin 28 extending 16 partially into the interior 20 of the die. Thepin 28 extends into the die 16 through anaperture 30 in theside 17 of thedie 16. One ormore bearings 21 are preferably mounted or seated within theaperture 30 to rotatably support thepin 28. For example, thebearings 21 can include thrust and side load bearings, as is known in the art. - In another embodiment, as illustrated in FIGS. 5 and 6, the
die 16 has first andsecond sides 17 a, b at least partially defining the interior 20 of the die. Thepin 28 extends from thefirst side 17 a to thesecond side 17 b of the die 16 so as to traverse the interior 20 of the die. Thefirst side 17 a of the die 16 defines a correspondingaperture 30 a through which thepin 28 extends, and thesecond side 17 b of the die 16 defines a correspondingaperture 30 b that is structured to receive the end of thepin 28.Bearings 21 a, b preferably are mounted or seated within theapertures 30 a, b of the first andsecond sides 17 a, b of the die 16 to rotatably support thepin 28 within each correspondingaperture 30 a, b. As illustrated in FIGS. 12A-12C, theapertures 30 a, b can be offset in relation to the interior 20 of the die 16 or, as illustrated in FIGS. 13A-13B, theapertures 30 a, b can be centered in relation to the interior 20 of thedie 16. Similarly, theaperture 30 forpins 28 that extend only partially into the interior 20 of the die 16, as is illustrated in FIGS. 2 and 4, also can be offset or centered in relation to the interior of the die. - In another embodiment (not shown), the
die 16 is an “open” die. In this regard, theinterior 20 of the die 16 is defined by two lateral sides and a bottom side, which can include a worktable or similar support surface. Therotatable pin 28 extends at least partially into the interior 20 of the die 16 through the open topside of the die. The lateral sides of the die preferably include bracing to support the sides during operation. - As illustrated in FIGS. 2 and 5, the
apparatus 14 includes at least onemotor 32 having arotatable spindle 34 that is in rotatable communication with thepin 28 such that the pin extends from the spindle at least partially into the interior 20 of thedie 16. Thespindle 34 preferably includes a chuck or collet (not shown), as is known in the art, structured to releasable receive and secure one end of thepin 28. For example, as illustrated in FIGS. 12D and 13C, thepin 28 can have a generally circular cross-sectional configuration that is received by a collet (not shown) and can include astop 27 a for the collet, as well as a flat 27 b structured to receive the set screw, as is known in the art. - The
motor 32 includes a device, such as a CNC machine, milling machine or drill (not shown), that is structured to rotate thespindle 34 andpin 28, as indicated by thearrows 25 in FIGS. 2 and 5. The specifications of themotor 32 will depend on the dimensions and material properties of theworkpiece 22. For example, according to one embodiment, a 35horsepower motor 32 can be used to mix ¼inch aluminum workpieces 22. Themotor 32 can be supported on the die 16 by a support structure and fasteners (not shown), but preferably is removable from the die so that the die can be replaced for purposes of repair or to substitute a different die to accommodate variations in the configuration or dimensions of theworkpieces 22 and/or resultingpreforms 26. When operating theapparatus 14, additional support preferably is provided underneath and around thedie 16, such as a worktable and bracing (not shown), to support the die and to prevent movement of the die relative to themotor 32. Themotor 32 can be manually operated, but preferably is in electrical communication through suitable electrical oroptical wiring 35 with a computer ormicroprocessor 33 operating under software control. - The
motors 32 illustrated in FIGS. 2 and 5 are positioned on the topside of the die 16, and thepins 28 extend vertically into the interior 20 of the die from the topside toward the bottom side of the die. However, the placement of themotor 32 is not limited to the topside of the die 16, as the motor can be positioned on a lateral side or the bottom side of the die, such that the correspondingpin 28 extends into the interior 20 of the die horizontally from one lateral side toward the opposite lateral side or vertically from the bottom side toward the topside, respectively. Thepin 28 also can extend into the interior 20 of the die 16 angularly from one side toward an adjacent side or toward the opposite side. - Referring to FIG. 7, in one embodiment of the present invention the
motor 32 comprises a milling machine to which thedie 16 is attached via thepin 28. In this regard, the end of thepin 28 opposite themotor 32 has a diameter larger than the diameter of theaperture 30 b defined by thesecond side 17 b of the die 16 thereby forming abacking 36 to support the die. One ormore bearings 31 are preferably positioned between the outer surface of thesecond side 17 b of thedie 16 and thebacking 36 to thereby facilitate rotation of the backing relative to the die. For example, as illustrated in FIG. 7, thebearings 31 are mounted to, or seated within, the backing 36 of thepin 28. As described above, additional support is preferably provided underneath and around thedie 16, such as a worktable and bracing (not shown), to support the die and to prevent movement of the die relative to the milling machine. - In other embodiments, the
apparatus 14 includes a plurality of rotatable pins 28. The plurality ofpins 28 can extend partially into the interior 20 of the die 16, as illustrated in FIG. 2, and/or can extend from thefirst side 17 a to thesecond side 17 b of the die so as to traverse the interior of the die, as illustrated in FIG. 5. Regarding the orientation of thepins 28 relative to the interior 20 of the die 16, thepins 28 can extend from the topside of the die toward the bottom side of the die, from the bottom side of the die toward the topside of the die, from one lateral side toward the opposite lateral side, and/or angularly between two adjacent sides or two opposite sides. Referring to FIG. 8, twopins 28 are shown traversing the interior 20 of the die 16 in a side-by-side configuration. In other embodiments (not shown), thepins 28 are positioned or spaced along the length of the interior 20 of the die 16 in either a straight-line or staggered configuration. Thepins 28 also can be spaced along the length of the interior 20 of the die 16 in a side-by-side configuration. As discussed above, forpins 28 extending partially into the interior 20 of the die 16, the pins can be rotatably supported within the correspondingaperture 30 defined by therespective side 17 of the die withbearings 21. Forpins 28 that traverse the interior 20 of the die 16, the pins can be rotatably supported within the correspondingapertures 30 a, b defined by therespective sides 17 a, b of the die withbearings 21 a, b, and in the case of pins defining abacking 36, withbearings 31. - For the embodiments of the
apparatus 14 that include two ormore pins 28, the apparatus can include a plurality ofmotors 32, each having arotatable spindle 34 that is in rotatable communication with acorresponding pin 28. Eachmotor 32 can be manually operated, but preferably all of the motors are in electrical communication through suitable electrical oroptical wiring 35 with a computer ormicroprocessor 33 operating under software control. Themotors 32 can be structured to rotate thepins 28 in the same direction, in opposite directions, or a combination of both. - In other embodiments of the present, the
apparatus 14 includes amotor 32 and adrive assembly 38 that is structured to rotatably communicate with one or more of thepins 28. For example, in one embodiment (not shown), thedrive assembly 38 includes a shaft rotatably mounted within an aperture extending through one side of the die. One end of the shaft is structured to be rotatably received by the spindle of a motor, while the other end of the shaft includes a chuck or collet for receiving and securing an end of a corresponding pin. The chuck or collet preferably is recessed flush within the corresponding side of the die so as not to obstruct movement of the workpiece through the interior of the die. The aperture preferably includes one or more bearings mounted therein to rotatably support the shaft. The aperture preferably is sealed, for example, using a metal cover with an elastomeric o-ring or the like, as is known in the art, to prevent material or other contaminants from entering the aperture and damaging the shaft or a bearing. - According to another embodiment, the
drive assembly 38 of theapparatus 14 includes arotatable turret 40, such as the one illustrated in FIG. 15, to which two ormore pins 28 are rotatably mounted. Each of thepins 28 extends from theturret 40 at least partially into the interior 20 of thedie 16. Theturret 40 is in rotatable communication with at least onespindle 34 of at least onemotor 32 and is structured to individually rotate each of thepins 28 in correspondingfirst directions 42 and to collectively rotate the pins in asecond direction 44. More specifically, theturret 40 transmits the torque generated by themotor 32 from thespindle 34 to thepins 28 both individually and collectively. The correspondingfirst directions 42 of rotation of theindividual pins 28 can be the same as thesecond direction 44, as illustrated in FIG. 9, or can be opposite to thesecond direction 44, as illustrated in FIG. 10. In addition, as illustrated in FIG. 1, the correspondingfirst directions 42 can include rotating at least two of thepins 28 in opposite directions. - According to one embodiment, as illustrated in FIG. 15, the
turret 40 includes abody 52 and afirst shaft 46. Thefirst shaft 46 extends from thebody 52 through anaperture 30 defined by a side of the die 16 to aspindle 34 of amotor 32, as described above for thepin 28. Thespindle 34 preferably includes a chuck or collet (not shown), as is known in the art, for releasably receiving and securing the end of thefirst shaft 46. Bearings (not shown) are preferably mounted or seated within theaperture 30 to rotatably support thefirst shaft 46 of theturret 40 within theaperture 30. Thebody 52 of theturret 40 preferably includes a plurality of chucks orcollets 43 rotatably mounted to the body using bearings (not shown). Each chuck orcollet 43 is structured to releasably receive and secure an end of acorresponding pin 28. Eachpin 28 extends from thebody 52 of theturret 40 partially into the interior 20 of thedie 16. So as not to obstruct the flow of the workpiece through the interior 20 of the die 16, the side of the die preferably defines a recess (not shown) configured to receive thebody 52 of theturret 40 so that the body of the turret does not extend into the interior of the die. - The
first shaft 46 is structured to individually rotate each of thepins 28 in correspondingfirst directions 42. According to one embodiment, as illustrated in FIG. 15, thefirst shaft 46 includes agear 46 a that rotatably communicates withcorresponding gears 43 a attached to each of the chucks orcollets 43. As thefirst shaft 46 rotates, as indicated byarrow 46 b, the first shaft transmits the torque generated by themotor 32 from thespindle 34 to the chuck orcollets 43, through the corresponding gears 46 a, 43 a. The chucks orcollets 43 then rotate thereby rotating thepins 28 individually in thefirst direction 42. - According to the embodiment illustrated in FIG. 15, the
turret 40 includes asecond shaft 48 that extends through anaperture 30 defined by the side of the die 16 to aspindle 34 of amotor 32, as described above for thepin 28. Thespindle 34 preferably includes a chuck or collet (not shown), as is known in the art, for releasably receiving and securing the end of thesecond shaft 48. Bearings (not shown) are preferably mounted or seated within theaperture 30 to rotatably support thesecond shaft 48 of theturret 40 within theaperture 30. Thesecond shaft 48 is structured to collectively rotate thepins 28 in asecond direction 44. According to one embodiment, as illustrated in FIG. 15, thesecond shaft 48 includes agear 48 a that rotatably communicates with acorresponding gear 52 a defined by the exterior of thebody 52 of theturret 40. As thesecond shaft 48 rotates, as indicated byarrow 48 b, the second shaft transmits the torque generated by themotor 32 from thespindle 34 to thebody 52 of theturret 40, through the corresponding gears 48 a, 52 a. Thebody 52 of theturret 40 then rotates thereby rotating thepins 28 collectively in thesecond direction 44. By varying the rate of rotation of the first andsecond shafts pins 28 individually and collectively can be modified. - In an alternate embodiment (not shown), the first and
second shafts turret 40 are connected together using suitable gearing to a third shaft that connects to a spindle of a motor. According to this embodiment, the rate of rotation ofpins 28 individually and collectively can be modified by changing the ratio of the gearing between the first and second shafts and the third shaft. - According to another embodiment (not shown), the
turret 40 includes first and second parts. The first part of the turret is similar to the embodiments described above. The second part of the turret includes a body and a shaft extending therefrom that is rotatably mounted to the side of the die opposite the first part of the turret. The body of the second part of the turret includes a plurality of chucks or collets for releasably receiving and securing the other end of each corresponding pin so that the pins traverse the interior of the die. The second part of the turret is passive in that the second part does not transmit torque to the pins. Rather, each chuck or collet of the second part of the turret is structured to individually rotate with the corresponding pin as the pins are individually rotated by the chucks or collets of the first part of the turret and the second part is structured to rotate with the pins as the pins are collectively rotated by the first part. So as not to obstruct the movement of the workpiece through the interior of the die, preferably the first and second sides of the die each define a recess configured to receive the corresponding first and second parts of the turret so that the first and second parts do not extend into the interior of the die. - As illustrated in FIGS. 2, 5,7, and 14, the
apparatus 14 preferably includes aram 37 structured to urge theworkpiece 22 through the interior 20 of the die 16 from thefirst aperture 18 a to thesecond aperture 18 b. Theram 37 can be powered using a hydraulic, pneumatic, orelectrical power source 39, as is known in the art. Theram 37 can be operated manually, but preferably is in electrical communication through suitable electrical oroptical wiring 45 with a computer ormicroprocessor 33 operating under software control. Theram 37 preferably stops short of contacting thepins 28, then anotherworkpiece 22 can be added and the process resumes. - Each
pin 28 is structured to at least partially stir theworkpiece 22 as the workpiece moves through the interior 20 of the die 16 to thereby refine the grain structure of the workpiece. More specifically, as illustrated in FIGS. 4, 6, 8, 12D, and 13C, eachpin 28 preferably includesthreads 29 that will mix or stir theworkpiece 22 as the workpiece is urged by theram 37 through the interior 20 of the die 16 from thefirst aperture 18 a to thesecond aperture 18 b. This process is similar to friction stir welding wherein a rotating threaded pin is inserted between the opposing faces of a pair of workpieces while urging the workpieces together. See U.S. Pat. No. 5,460,317 to Thomas et al. for a general discussion of friction stir welding, the entire contents of which are incorporated herein by reference. - The rotation of the threaded pin or pins28 against and through the
workpiece 22 creates friction that generates sufficient heat energy to plasticize the workpiece material proximate to the rotating pin or pins. Advantageously, as the material of the workpiece 22 passes the rotating pin or pins 28 of theapparatus 14 and thereafter cools, apreform 26, such as the one illustrated in FIG. 14, will be formed having a refined grain structure with grains having an equiaxed shape and grain sizes ranging in order of magnitude from approximately 0.0001 to approximately 0.0002 inches (approximately 3 microns to approximately 5 microns). The refined grain structure of thepreform 26 resists the formation and propagation of micro-cracks and exhibits improved strength, ductility and toughness, as well as improved intergranular corrosion and fatigue resistance. - According to one embodiment, the
workpiece 22 comprises metal chips (e.g., chips and shavings produced during machining process) or a combination of metal chips, shavings and fine ceramic particles (e.g., silicon carbide whiskers). As theworkpiece 22 is driven into the at least onepin 28, thepin 28 breaks up and mixes the workpiece components (chips and ceramic powder) and consolidates the components into aperform 26. This embodiment can serve as a recycling tool by forming a structural member or perform from manufacturing scrap (chips and shavings) or produce a metal matrix composite without using metal powder or sintering. - As illustrated in FIGS. 2, 5, and7, the
interior 20 of the die 16 preferably defines achamber 58 adjacent thesecond aperture 18 b that is structured to exert pressure on theworkpiece 22 to re-consolidate the workpiece after the workpiece has been mixed by the pin or pins 28. For example, thechamber 58 can be formed by a further reduction in the cross-sectional area of the interior 20 of thedie 16. The pressure exerted on theworkpiece 22 by thechamber 58 forces any air or other gases from the material that may have been mixed into the material by the rotating pin or pins 28 to thereby prevent porosity within thepreform 26. - As illustrated in FIG. 14, the
preform 26 comprises abody 56 having predetermined dimensions, which as discussed above, will depend on the configuration and dimensions of the interior 20 of thedie 16. Thebody 56 comprises a refined grain structure having a cross-section comprising a curvilinear configuration created by the stirring or mixing action of the rotating pin or pins 28. A photograph of the curvilinear cross-section of apreform 26 having a refined grain structure formed according to the present invention is illustrated at FIG. 15. As discussed above, thepreform 26 can be constructed of a variety of material, as required by the specific design loads, environmental conditions, and specifications of the resulting structural assembly to be formed from the preform. Forpreforms 26 that will be used in aerospace applications, where weight and strength are of critical concern, the preform preferably is formed of aluminum, an aluminum alloy, titanium, a titanium alloy or a steel alloy. - Advantageously, because of the refined grain structure, a
preform 26 formed according to the present invention will have an elongation of between about 15% and about 35% and, more preferably, an elongation of greater than about 20%. For example, AA 2195 aluminum alloys and AA 2219 aluminum alloys with a refined grain structure according to the present invention can have an elongation along the longitudinal axis of approximately 21.5% and approximately 29%, respectively. - A further increase in elongation can be obtained by an additional heat treatment, such as an annealing process or precipitation hardening. Annealing refers to a heat treatment in which material is exposed to an elevated temperature for an extended time period and then slowly cooled. The annealing process consists of three stages. First, the
preform 26 is heated to a desired temperature, which will depend on the particular composition of the material. For example, aperform 26 formed of an aluminum alloy can be annealed around 700° F. Second, the material is held so that thepreform 26 can soak at that temperature for a predetermined period of time. Third, thepreform 26 is cooled to room temperature. For example, aperform 26 formed of an aluminum alloy can be soaked for approximately 8 hours. It has been found that a full annealing process increased the percent elongation of the AA 2195 aluminum alloys and AA 2219 aluminum alloys having a refined grain structure formed according to the present invention from approximately 21.5% to approximately 26% and from approximately 29% to approximately 34%, respectively. - Precipitation hardening of metal alloys is a process whereby the mechanical properties of the metal alloy are improved by the formation of uniformly dispersed particles or precipitates of one or more secondary phases within the original phase matrix. Precipitation hardening requires that the metal alloy undergo two heat treatment processes, the first process being a solution heat treatment and the second process being a precipitation heat treatment. Referring to FIG. 18A, there is shown a hypothetical phase diagram for a precipitation-hardenable metal alloy composed of alloying elements A and B. Although FIG. 18A illustrates a phase diagram for a binary system, precipitation-hardenable metal alloys may contain two or more alloying elements. For a metal alloy to be precipitation hardenable, the alloy must have an appreciable maximum solubility of one element in the other, on the order of several percent, and a solubility limit that rapidly decreases in concentration of the major element with temperature reduction. Both of these requirements are satisfied by the hypothetical phase diagram of FIG. 18A, where the maximum solubility is designated by M. Additionally, the composition of a precipitation-hardenable metal alloy must be less than the maximum solubility M. Examples of some of the binary and ternary metal alloys that are precipitation hardenable include aluminum-calcium, aluminum-chromium, aluminum-cobalt, aluminum-copper, aluminum-iron-titanium, aluminum-gallium-germanium, aluminum-gallium-indium, aluminum-germanium-tin, aluminum-lithium, aluminum-lithium-magnesium, aluminum-manganese, aluminum-molybdenum, aluminum-nickel-titanium, aluminum-niobium, aluminum-silicon, copper-beryllium, copper-tin, magnesium-aluminum, as well as some ferrous alloys.
- In the hypothetical binary system illustrated in FIG. 18A, element A designates the original phase matrix, while element B designates the solute or secondary element. To form the uniformly dispersed particles or precipitates of the secondary alloying element within the original phase matrix of the
preform 26, the phase associated with the secondary alloying element must first be completely dissolved, such that the only remaining phase is the phase associated with the original phase matrix. The phase associated with the secondary alloying element is dissolved through a solution heat treatment process at a first predetermined temperature schedule. To illustrate the solution heat treatment process, reference is made to FIG. 18A and the metal alloy composed of a predetermined percentage of elements A and B designated by C1. At ambient temperature, the hypothetical metal alloy of thepreform 26 will be in an equilibrium state and will contain both the α phase of element A and the β phase of element B. During the solution heat treatment process, the temperature of thepreform 26 is raised to temperature T0. At temperature T0, the β phase or solute atoms of element B begin to dissolve. As shown in FIG. 18B, thepreform 26 is maintained at temperature T0 for a sufficient period of time, designated t1, to allow all of the β phase to dissolve so that the alloy contains only the α phase of composition C1. - Once the β phase has completely dissolved, the
preform 26 is rapidly cooled or quenched to ambient temperature, which is designated by T1, as shown in FIGS. 18A and 18B. The rapid cooling inhibits the formation of the β phase so that only the α phase solid solution supersaturated with B atoms is present. However, thepreform 26 in the α phase at this temperature is in a nonequilibrium state with an incomplete temper, such that generally the β phase will gradually begin to form in the existing α phase matrix. In this nonequilibrium state, most metal alloys are relatively soft and weak. - Following solution heat treating, precipitation hardening is completed by precipitation heat treating the
preform 26 through natural or artificial aging of the preform to the desired temper at a predetermined temperature schedule. Referring again to FIGS. 18A and 18B, precipitation heat treating or aging requires that thepreform 26 undergo an isothermal heat treatment whereby the temperature of the assembly is raised to a predetermined temperature, designated by T2, for a predetermined amount of time, designated t2. The temperature T2 is within the α and β two-phase region of the hypothetical phase diagram and is a temperature at which the diffusion rates for the B atoms become appreciable. The diffusion of the B atoms into a β phase results in the formation of finely dispersed particles of the B alloy element. Once the desired amount of diffusion has taken place, thepreform 26 may be cooled to room temperature. - The character of the β phase particles, and thus the strength and hardness for a given metal alloy used to form the
preform 26 is dependent upon the precipitation temperature, designated T2, and the aging time at this temperature, designated t2. Notably, some metal alloys will age at room temperature over an extended period of time, commonly denoted natural aging, while other metal alloys require artificially raised temperatures, commonly denoted artificial aging. - Referring now to FIG. 18C, there is shown a binary system phase diagram for aluminum and copper adapted fromMetals Handbook: Metallography, Structures and Phase Diagrams, Vol. 8, 8th edition, ASM Handbook Committee, T. Lyman Editor, American Society for Metals, 1973, p. 259, to further illustrate the solution heat treatment and precipitation heat treatment processes. From the diagram, the temperature range (previously designated T0) to solution heat treat an aluminum-copper metal alloy having a known composition of wt % copper (previously designated C1) so as to completely dissolve the copper atoms can be determined. The time period necessary to completely dissolve the copper atoms, previously designated t1 hours, is dependent upon the material composition, C1, and the temperature, T0, and can be readily determined by those skilled in the art. Upon completing the solution heat treating, the resulting alloy has an incomplete temper and is in a nonequilibrium state. The precipitation heat treatment process is then conducted at a temperature range of approximately 100° C. to approximately 300° C. (previously designated T2) for t2 hours to complete the temper and stabilize the material properties. The time period, t2, being dependent upon the material composition, C1, and the temperature, T2, and can be readily determined by those skilled in the art.
- Grain growth can be controlled during the annealing and precipitation hardening processes by controlling thermal gradients within the material or by stretching the
preform 26 past the critical strain limits that nucleate grain growth. In addition, it has been found that heating theworkpiece 22, thedie 16 and/or the pin or pins 28 before and/or during the mixing operation results in thepreform 26 better retaining the refined grain structure during subsequent annealing or precipitation hardening. According to one embodiment, theworkpiece 22, thedie 16, and/or pin or pins 28 are heated to between about 600° F. and about 1000° F., and more preferably are heated to about 750° F. More preferably, theworkpiece 22, thedie 16, and/or pin or pins 28 are heated to about the solution heat treatment temperature of the material forming the workpiece. For purposes of example only and not limitation, theworkpiece 22, die 16 and/or pin or pins 28 can be heated using electrical current, a resistance heating coil, an induction heating coil, a quartz lamp, a gas torch, or a laser. For example, the assignee of the present application has developed methods and apparatus for heating a friction stir welding probe, which is similar to thepins 28 of the present invention, as disclosed in commonly owned U.S. patent application Ser. No. 10/035,865 entitled “High Strength Friction Stir Welding” filed on Dec. 26, 2001, the entire disclosure of which is hereby incorporated by reference. - To control the temperature of the
workpiece 22 during the operation of theapparatus 14 and, more preferably, to control the temperature of the workpiece so that the temperature does not exceed the solution heat treatment temperature of the material used to form the workpiece, the die 16 can be cooled. For example, the die 16 can include internal piping attached any of a number of cooling systems, as are known in the art, for supplying gaseous or liquid coolant to the die and for transporting heat away from the die. - According to one embodiment, as illustrated in FIG. 14, the
apparatus 14 includes atemperature control unit 53 in electrical communication through suitable electrical oroptical wiring 55 with a computer ormicroprocessor 33 operating under software control. Thetemperature control unit 53 is in electrical communication with a heating system 53 a andcooling system 53 b, as described above, through suitable electrical oroptical wiring 53 c. In turn, the heating system 53 a andcooling system 53 b are in thermal communication with the die 16, as illustrated in FIG. 14 byreference numerals optical wiring 50 withtemperature control unit 53. - As illustrated in FIG. 14, the
apparatus 14 can include acooling unit 59 attached directly to the die 16 for cooling theworkpiece 22. For example, the cooling unit can include jets (not shown) for spraying gaseous or liquid coolant onto thepreform 26 to thereby quench the preform. Theapparatus 14 preferably includes an insulatingblock 47 between the coolingunit 59 and thedie 16. - During operation of the
apparatus 14, aworkpiece 22 is positioned adjacent thefirst aperture 18 a of thedie 16. Thepower source 39 for theram 37 is then engaged manually using a control panel (not shown) located on thepower source 39 or using thecomputer 33, or alternatively, thecomputer 33 can be preprogrammed to automatically engage the power source. Theram 37 moves into contact with theworkpiece 22 and begins to force the workpiece through thefirst aperture 18 a and into the interior 20 of thedie 16. As described above, theinterior 20 of the die 16 can be structured to shape or form theworkpiece 22, such as through a reduction in the cross-sectional area of the workpiece. - Upon engagement of the
power source 39 for theram 37, the motor ormotors 32 connected to one or more threadedpins 28 that extend at least partially into the interior 20 of the die 16 are engaged. The motor ormotors 32 can be engaged manually using a control panel (not shown) located on each motor or using thecomputer 33. Alternatively, thecomputer 33 can be preprogrammed to automatically engage the motor ormotors 32 when engaging thepower source 39 for theram 37. As theram 37 forces theworkpiece 22 through the interior 20 of the die 16 from thefirst aperture 18 a to thesecond aperture 18 b, the rotation of the pin or pins 28 against and through the workpiece creates friction that generates sufficient heat energy to plasticize the workpiece proximate to the rotating pin or pins. The number ofpins 28, as well as the spacing, configuration and orientation of the pins within theinterior 20 of the die 16 will depend on the dimensions and configuration of theworkpiece 22, and preferably is selected such that the entire workpiece is mixed or stirred by the pin or pins to avoid a “banded” grain pattern, i.e., bands of mixed workpiece material with gaps of unmixed material therebetween. - The
workpiece 22, die 16 and/or the pin or pins 28 can be heated before and/or during the mixing operation. Preferably the temperature of theworkpiece 22 within thedie 16 is maintained at approximately the solution heat treatment temperature of the material forming the workpiece. According to one embodiment, thecomputer 33 engages thetemperature control unit 53, including communicating to the temperature control unit the desired temperature of theworkpiece 22, die 16, and/or pin or pins 28. Thetemperature control unit 53 periodically obtains temperature readings from the temperature sensors 41 and compares the temperature reading to the desired temperature communicated to the temperature control unit by thecomputer 33. If the temperature reading exceeds the desired temperature reading, then thetemperature control unit 53 engages thecooling system 53 b and disengages the heating system 53 a. If the temperature reading is below the desired temperature reading, then thetemperature control unit 53 engages the heating system 53 a and disengages thecooling system 53 b. - As the workpiece22 passes the rotating pin or pins 28, the
interior 20 of the die 16 preferably includes achamber 58 adjacent thesecond aperture 18 b that is structured to exert pressure on theworkpiece 22 to re-consolidate the workpiece after the workpiece has been mixed by the pin or pins 28. Thereafter, theworkpiece 22 cools to form apreform 26 having a refined grain structure, which preform exits theapparatus 14 through thesecond aperture 18 b of thedie 16. If desired, thepreform 26 can undergo additional heat treatments to further improve the material properties of the preform. Thepreform 26 can then be machined, using known machining methods, into a structural member that can be connected to other structural members using fasteners or welding techniques to form a structural assembly, such as the frame of an aerospace vehicle. - Referring now to FIG. 19, there is illustrated the operations performed when operating on a workpiece, according to one embodiment of the present invention. The method of manufacturing includes moving a workpiece through a die. See
block 61. Concurrently with the moving step, the workpiece is mixed with at least one rotating pin to thereby refine the grain structure of the workpiece. Seeblock 62. In one embodiment, the workpiece is heated concurrently with the mixing step. Seeblock 67. In another embodiment, the pin and/or die are heated concurrently with the mixing step. Seeblock 68. Preferably, the pin and/or die are heated to the solution heat treatment temperature of the material used to form the workpiece. For example, the heating step can comprise heating the pin and/or die to a temperature between about 600° F. and about 1000° F. In another embodiment, the die is cooled concurrently with the mixing step. Seeblock 69. In yet another embodiment, the mixing step comprises individually rotating a plurality of pins in corresponding first directions and collectively rotating the plurality of pins in a second direction. Seeblock 63. In one embodiment, the corresponding first directions are the same as the second direction. Seeblock 64. In another embodiment, the corresponding first directions are opposite to the second direction. Seeblock 65. In still another embodiment, the corresponding first directions comprise rotating at least two of the pins in opposite directions. Seeblock 66. - The material properties of the workpiece can be further developed through selective heat treating. In one embodiment, the workpiece is solution heat treated prior to the moving step. See
block 60. In another embodiment, the workpiece is solution heat treated at a predetermined temperature schedule after the mixing step. Seeblock 70. In yet another embodiment, the workpiece is precipitation heat treated by aging at a second predetermined temperature schedule after the solution heat treating step. Seeblock 71. - Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
Claims (22)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/609,951 US20040004107A1 (en) | 2002-05-14 | 2003-06-30 | Method and apparatus for producing a refined grain structure |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/145,009 US6726085B2 (en) | 2002-05-14 | 2002-05-14 | Method and apparatus for producing a refined grain structure |
US10/609,951 US20040004107A1 (en) | 2002-05-14 | 2003-06-30 | Method and apparatus for producing a refined grain structure |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/145,009 Division US6726085B2 (en) | 2002-05-14 | 2002-05-14 | Method and apparatus for producing a refined grain structure |
Publications (1)
Publication Number | Publication Date |
---|---|
US20040004107A1 true US20040004107A1 (en) | 2004-01-08 |
Family
ID=29548258
Family Applications (3)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/145,009 Expired - Fee Related US6726085B2 (en) | 2002-05-14 | 2002-05-14 | Method and apparatus for producing a refined grain structure |
US10/606,564 Expired - Lifetime US6865919B2 (en) | 2002-05-14 | 2003-06-26 | Method and apparatus for producing a refined grain structure |
US10/609,951 Abandoned US20040004107A1 (en) | 2002-05-14 | 2003-06-30 | Method and apparatus for producing a refined grain structure |
Family Applications Before (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/145,009 Expired - Fee Related US6726085B2 (en) | 2002-05-14 | 2002-05-14 | Method and apparatus for producing a refined grain structure |
US10/606,564 Expired - Lifetime US6865919B2 (en) | 2002-05-14 | 2003-06-26 | Method and apparatus for producing a refined grain structure |
Country Status (1)
Country | Link |
---|---|
US (3) | US6726085B2 (en) |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20040020970A1 (en) * | 2000-07-25 | 2004-02-05 | Frank Palm | Laser supported friction stir welding method |
US20040118899A1 (en) * | 2002-12-20 | 2004-06-24 | Kinya Aota | Friction stir welding method |
US20040159696A1 (en) * | 2003-02-18 | 2004-08-19 | Innovative Technology Licensing, Llc | Thick-section metal forming via friction stir processing |
US6802444B1 (en) * | 2003-03-17 | 2004-10-12 | The United States Of America As Represented By The National Aeronautics And Space Administration | Heat treatment of friction stir welded 7X50 aluminum |
US20060208032A1 (en) * | 2005-03-16 | 2006-09-21 | Siemens Westinghouse Power Corporation | Manufacture of specialized alloys with specific properties |
US20100069560A1 (en) * | 2006-12-20 | 2010-03-18 | Basell Poliolefine Italia S.R.L. | Filled polyolefin compositions |
US7905383B1 (en) * | 2009-12-22 | 2011-03-15 | Chung Shan Institute Of Science And Technology, Armaments Bureau, M.N.D. | Manufacturing method of metal matrix composite using friction stir welding |
US8556156B1 (en) * | 2012-08-30 | 2013-10-15 | Apple Inc. | Dynamic adjustment of friction stir welding process parameters based on weld temperature |
Families Citing this family (39)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6726085B2 (en) * | 2002-05-14 | 2004-04-27 | The Boeing Company | Method and apparatus for producing a refined grain structure |
US6854634B2 (en) * | 2002-05-14 | 2005-02-15 | The Boeing Company | Method of manufacturing rivets having high strength and formability |
AU2003299073A1 (en) * | 2002-09-30 | 2004-04-19 | Zenji Horita | Method of working metal, metal body obtained by the method and metal-containing ceramic body obtained by the method |
US20050271496A1 (en) * | 2002-10-17 | 2005-12-08 | National Institute For Materials Science | Formed product and method for production thereof |
US6884966B2 (en) * | 2002-10-22 | 2005-04-26 | The Boeing Company | Method and apparatus for forming and heat treating structural assemblies |
GB0225518D0 (en) * | 2002-11-01 | 2002-12-11 | Airbus Uk Ltd | Welding method |
US7341176B2 (en) * | 2002-11-26 | 2008-03-11 | Volvo Aero Corporation | Method of tying two or more components together |
US6912885B2 (en) * | 2002-12-30 | 2005-07-05 | The Boeing Company | Method of preparing ultra-fine grain metallic articles and metallic articles prepared thereby |
US7523850B2 (en) * | 2003-04-07 | 2009-04-28 | Luxfer Group Limited | Method of forming and blank therefor |
KR101067033B1 (en) * | 2003-04-25 | 2011-09-22 | 혼다 기켄 고교 가부시키가이샤 | Tubular metal body, method of producing same, liner for pressure vessel and method of producing same |
US20080213720A1 (en) * | 2003-05-13 | 2008-09-04 | Ultradent Products, Inc. | Endodontic instruments manufactured using chemical milling |
US20050051602A1 (en) * | 2003-05-13 | 2005-03-10 | Babb Jonathan Allyn | Control system for friction stir welding of metal matrix composites, ferrous alloys, non-ferrous alloys, and superalloys |
US7448528B2 (en) * | 2003-08-12 | 2008-11-11 | The Boeing Company | Stir forming apparatus and method |
US7398911B2 (en) * | 2003-12-16 | 2008-07-15 | The Boeing Company | Structural assemblies and preforms therefor formed by friction welding |
US7225967B2 (en) | 2003-12-16 | 2007-06-05 | The Boeing Company | Structural assemblies and preforms therefor formed by linear friction welding |
US20060032849A1 (en) * | 2004-07-29 | 2006-02-16 | Machrowicz Tad V | Integrated die forming and welding process and apparatus therefor |
JP4468125B2 (en) * | 2004-09-27 | 2010-05-26 | 三菱重工業株式会社 | Friction stir welding method and apparatus |
US20060177284A1 (en) * | 2005-02-07 | 2006-08-10 | The Boeing Company | Method for preparing pre-coated aluminum and aluminum-alloy fasteners and components having high-shear strength and readily deformable regions |
US7665212B2 (en) * | 2005-02-23 | 2010-02-23 | Ultradent Products, Inc. | Methods for manufacturing endodontic instruments |
US7743505B2 (en) | 2005-02-23 | 2010-06-29 | Ultradent Products, Inc. | Methods for manufacturing endodontic instruments from powdered metals |
WO2006116288A2 (en) * | 2005-04-22 | 2006-11-02 | Regents Of The University Of Michigan | Rotatable multi-pin apparatus, and process for friction driven stitch welding and structural modification of materials |
US7163138B1 (en) | 2005-05-09 | 2007-01-16 | The United States Of America As Represented By The Secretary Of The Navy | Friction stirred introduction of particles into a metallic substrate for surface durability treatment |
US9511446B2 (en) | 2014-12-17 | 2016-12-06 | Aeroprobe Corporation | In-situ interlocking of metals using additive friction stir processing |
US8632850B2 (en) | 2005-09-26 | 2014-01-21 | Schultz-Creehan Holdings, Inc. | Friction fabrication tools |
US9266191B2 (en) * | 2013-12-18 | 2016-02-23 | Aeroprobe Corporation | Fabrication of monolithic stiffening ribs on metallic sheets |
US9511445B2 (en) | 2014-12-17 | 2016-12-06 | Aeroprobe Corporation | Solid state joining using additive friction stir processing |
US20070138236A1 (en) * | 2005-12-20 | 2007-06-21 | The Boeing Company | Friction stir welded assembly and associated method |
US20080099533A1 (en) * | 2006-10-31 | 2008-05-01 | General Electric | Method for controlling microstructure via thermally managed solid state joining |
JP5250410B2 (en) * | 2008-12-26 | 2013-07-31 | 株式会社日立製作所 | Manufacturing method of composite material |
US8899467B1 (en) * | 2011-09-23 | 2014-12-02 | The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration | Ultrasonically-assisted thermal stir welding system |
JP5204928B1 (en) * | 2011-10-14 | 2013-06-05 | 日本車輌製造株式会社 | Friction stir welding equipment |
DE102011117961A1 (en) | 2011-11-08 | 2013-05-08 | Hochschule Für Angewandte Wissenschaften - Fachhochschule Kempten | Reibauftragsvorrichtung |
US20130125376A1 (en) | 2011-11-17 | 2013-05-23 | The Boeing Company | Method for preparing highly-deformable titanium and titanium-alloy one-piece fasteners and fasteners prepared thereby |
US8657179B1 (en) * | 2012-03-26 | 2014-02-25 | The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration | Weld nugget temperature control in thermal stir welding |
CN103008381B (en) * | 2012-12-11 | 2015-08-05 | 烟台大学 | A kind of method stirring shunting mould and application stirring shunting mould extrudate |
JP6084887B2 (en) * | 2013-04-16 | 2017-02-22 | 川崎重工業株式会社 | Friction stir welding apparatus and friction stir welding method |
WO2019016825A1 (en) * | 2017-07-19 | 2019-01-24 | Shiv Nadar University | An appartus and a method for processing stainless steel and an improved stainless steel for bioimplants thereof |
AU2018359514C1 (en) | 2017-10-31 | 2021-05-27 | MELD Manufacturing Corporation | Solid-state additive manufacturing system and material compositions and structures |
CN111168223A (en) * | 2020-01-03 | 2020-05-19 | 中国航空制造技术研究院 | Device and method for preparing aluminum matrix composite material by high-efficiency stirring |
Citations (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4063676A (en) * | 1974-12-02 | 1977-12-20 | The Welding Institute | Friction welding methods and apparatus |
US4260094A (en) * | 1978-06-06 | 1981-04-07 | Technisch Handels-En Adviesbureau Van Geffen B.V. | Method of interconnecting several parts, such as a piece of tubing and a plate, a tube or similar body |
US5460317A (en) * | 1991-12-06 | 1995-10-24 | The Welding Institute | Friction welding |
US5611479A (en) * | 1996-02-20 | 1997-03-18 | Rockwell International Corporation | Friction stir welding total penetration technique |
US5713507A (en) * | 1996-03-21 | 1998-02-03 | Rockwell International Corporation | Programmable friction stir welding process |
US5813592A (en) * | 1994-03-28 | 1998-09-29 | The Welding Institute | Friction stir welding |
US5829664A (en) * | 1996-11-15 | 1998-11-03 | Aluminum Company Of America | Resistance heated stir welding |
US5893507A (en) * | 1997-08-07 | 1999-04-13 | The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration | Auto-adjustable pin tool for friction stir welding |
US6398883B1 (en) * | 2000-06-07 | 2002-06-04 | The Boeing Company | Friction stir grain refinement of structural members |
US20020079351A1 (en) * | 2000-12-22 | 2002-06-27 | Mishra Rajiv S. | Metal superplasticity enhancement and forming process |
US20030085257A1 (en) * | 2001-11-02 | 2003-05-08 | The Boeing Company | Apparatus and method for forming weld joints having compressive residual stress patterns |
US20030111147A1 (en) * | 2001-12-18 | 2003-06-19 | Keener Steven G. | Method for preparing ultra-fine grain titanium and titanium-alloy articles and articles prepared thereby |
US20030116608A1 (en) * | 2001-12-26 | 2003-06-26 | The Boeing Company | High strength friction stir welding |
US20040020967A1 (en) * | 2002-05-14 | 2004-02-05 | The Boeing Company | Method of manufacturing rivets having high strength and formability |
US20040050907A1 (en) * | 1999-09-03 | 2004-03-18 | Dracup Brian J. | Friction stir welding as a rivet replacement technology |
US6754634B1 (en) * | 1998-04-01 | 2004-06-22 | William P. C. Ho | Method for scheduling transportation resources |
US6779707B2 (en) * | 1999-09-03 | 2004-08-24 | Lockheed Martin Corporation | Friction stir welding as a rivet replacement technology |
US20050035179A1 (en) * | 2003-08-12 | 2005-02-17 | The Boeing Company | Stir forming apparatus and method |
Family Cites Families (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4960163A (en) * | 1988-11-21 | 1990-10-02 | Aluminum Company Of America | Fine grain casting by mechanical stirring |
DE4120166C2 (en) * | 1991-06-19 | 1994-10-06 | Friedrichs Konrad Kg | Extrusion tool for producing a hard metal or ceramic rod with twisted inner holes |
US5160554A (en) * | 1991-08-27 | 1992-11-03 | Titanium Metals Corporation | Alpha-beta titanium-base alloy and fastener made therefrom |
DE19644447C2 (en) * | 1996-10-25 | 2001-10-18 | Friedrichs Konrad Kg | Method and device for the continuous extrusion of rods made of plastic raw material equipped with a helical inner channel |
US6045634A (en) * | 1997-08-14 | 2000-04-04 | Praxair S. T. Technology, Inc. | High purity titanium sputtering target and method of making |
US6168067B1 (en) * | 1998-06-23 | 2001-01-02 | Mcdonnell Douglas Corporation | High strength friction stir welding |
AU5121999A (en) * | 1998-07-24 | 2000-02-14 | Gibbs Die Casting Aluminum Corporation | Semi-solid casting apparatus and method |
JP3720240B2 (en) * | 2000-05-08 | 2005-11-24 | 日本軽金属株式会社 | Method for producing cathode for electrolytic deposition of nonferrous metal |
JP2002273579A (en) * | 2001-03-15 | 2002-09-25 | Hitachi Ltd | Method of joining iron-base material and structure for the same |
WO2003106098A1 (en) * | 2001-10-04 | 2003-12-24 | Smith International, Inc. | Method and apparatus for friction stir welding |
US6726085B2 (en) * | 2002-05-14 | 2004-04-27 | The Boeing Company | Method and apparatus for producing a refined grain structure |
-
2002
- 2002-05-14 US US10/145,009 patent/US6726085B2/en not_active Expired - Fee Related
-
2003
- 2003-06-26 US US10/606,564 patent/US6865919B2/en not_active Expired - Lifetime
- 2003-06-30 US US10/609,951 patent/US20040004107A1/en not_active Abandoned
Patent Citations (22)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4063676A (en) * | 1974-12-02 | 1977-12-20 | The Welding Institute | Friction welding methods and apparatus |
US4260094A (en) * | 1978-06-06 | 1981-04-07 | Technisch Handels-En Adviesbureau Van Geffen B.V. | Method of interconnecting several parts, such as a piece of tubing and a plate, a tube or similar body |
US5460317A (en) * | 1991-12-06 | 1995-10-24 | The Welding Institute | Friction welding |
US5460317B1 (en) * | 1991-12-06 | 1997-12-09 | Welding Inst | Friction welding |
US5813592A (en) * | 1994-03-28 | 1998-09-29 | The Welding Institute | Friction stir welding |
US5611479A (en) * | 1996-02-20 | 1997-03-18 | Rockwell International Corporation | Friction stir welding total penetration technique |
US5713507A (en) * | 1996-03-21 | 1998-02-03 | Rockwell International Corporation | Programmable friction stir welding process |
US5829664A (en) * | 1996-11-15 | 1998-11-03 | Aluminum Company Of America | Resistance heated stir welding |
US5893507A (en) * | 1997-08-07 | 1999-04-13 | The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration | Auto-adjustable pin tool for friction stir welding |
US6754634B1 (en) * | 1998-04-01 | 2004-06-22 | William P. C. Ho | Method for scheduling transportation resources |
US20040050907A1 (en) * | 1999-09-03 | 2004-03-18 | Dracup Brian J. | Friction stir welding as a rivet replacement technology |
US6779707B2 (en) * | 1999-09-03 | 2004-08-24 | Lockheed Martin Corporation | Friction stir welding as a rivet replacement technology |
US6398883B1 (en) * | 2000-06-07 | 2002-06-04 | The Boeing Company | Friction stir grain refinement of structural members |
US20020079351A1 (en) * | 2000-12-22 | 2002-06-27 | Mishra Rajiv S. | Metal superplasticity enhancement and forming process |
US6712916B2 (en) * | 2000-12-22 | 2004-03-30 | The Curators Of The University Of Missouri | Metal superplasticity enhancement and forming process |
US20030085257A1 (en) * | 2001-11-02 | 2003-05-08 | The Boeing Company | Apparatus and method for forming weld joints having compressive residual stress patterns |
US20030111147A1 (en) * | 2001-12-18 | 2003-06-19 | Keener Steven G. | Method for preparing ultra-fine grain titanium and titanium-alloy articles and articles prepared thereby |
US20030116608A1 (en) * | 2001-12-26 | 2003-06-26 | The Boeing Company | High strength friction stir welding |
US6780525B2 (en) * | 2001-12-26 | 2004-08-24 | The Boeing Company | High strength friction stir welding |
US20040020967A1 (en) * | 2002-05-14 | 2004-02-05 | The Boeing Company | Method of manufacturing rivets having high strength and formability |
US6843404B2 (en) * | 2002-05-14 | 2005-01-18 | The Boeing Company | Method of manufacturing rivets having high strength and formability |
US20050035179A1 (en) * | 2003-08-12 | 2005-02-17 | The Boeing Company | Stir forming apparatus and method |
Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20040020970A1 (en) * | 2000-07-25 | 2004-02-05 | Frank Palm | Laser supported friction stir welding method |
US6793118B2 (en) * | 2000-07-25 | 2004-09-21 | Eads Deutschland Gmbh | Laser supported friction stir welding method |
US20040118899A1 (en) * | 2002-12-20 | 2004-06-24 | Kinya Aota | Friction stir welding method |
US6866181B2 (en) * | 2002-12-20 | 2005-03-15 | Hitachi, Ltd. | Friction stir welding method |
US20040159696A1 (en) * | 2003-02-18 | 2004-08-19 | Innovative Technology Licensing, Llc | Thick-section metal forming via friction stir processing |
US6866180B2 (en) * | 2003-02-18 | 2005-03-15 | Rockwell Scientific Licensing, Llc | Thick-section metal forming via friction stir processing |
US6802444B1 (en) * | 2003-03-17 | 2004-10-12 | The United States Of America As Represented By The National Aeronautics And Space Administration | Heat treatment of friction stir welded 7X50 aluminum |
US20060208032A1 (en) * | 2005-03-16 | 2006-09-21 | Siemens Westinghouse Power Corporation | Manufacture of specialized alloys with specific properties |
US8298480B2 (en) | 2005-03-16 | 2012-10-30 | Siemens Energy, Inc. | Manufacture of specialized alloys with specific properties |
US20100069560A1 (en) * | 2006-12-20 | 2010-03-18 | Basell Poliolefine Italia S.R.L. | Filled polyolefin compositions |
US7905383B1 (en) * | 2009-12-22 | 2011-03-15 | Chung Shan Institute Of Science And Technology, Armaments Bureau, M.N.D. | Manufacturing method of metal matrix composite using friction stir welding |
US8556156B1 (en) * | 2012-08-30 | 2013-10-15 | Apple Inc. | Dynamic adjustment of friction stir welding process parameters based on weld temperature |
Also Published As
Publication number | Publication date |
---|---|
US6865919B2 (en) | 2005-03-15 |
US20040000576A1 (en) | 2004-01-01 |
US6726085B2 (en) | 2004-04-27 |
US20030218052A2 (en) | 2003-11-27 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6865919B2 (en) | Method and apparatus for producing a refined grain structure | |
Gangwar et al. | Friction stir welding of titanium alloys: A review | |
US6780525B2 (en) | High strength friction stir welding | |
Khodir et al. | Microstructure and mechanical properties of friction stir welded AA2024-T3 aluminum alloy | |
Liu et al. | Grain structure evolution, grain boundary sliding and material flow resistance in friction welding of Alloy 718 | |
Hasan et al. | Effect of pin tool flute radius on the material flow and tensile properties of dissimilar friction stir welded aluminum alloys | |
WO1998017836A1 (en) | Method of processing titanium alloys and the article | |
Aydin et al. | Effect of welding parameters on tensile properties and fatigue behavior of friction stir welded 2014-T6 aluminum alloy | |
Kimura et al. | Effect of friction welding condition and weld faying surface properties on tensile strength of friction welded joint between pure titanium and pure copper | |
Dorbane et al. | Effect of temperature on microstructure and fracture mechanisms in friction stir welded Al6061 joints | |
Abd Elnabi et al. | Optimization of process parameters for friction stir welding of dissimilar aluminum alloys using different Taguchi arrays | |
Saravanan et al. | Mechanical characterization of friction stir welded dissimilar aluminium alloy using Taguchi approach | |
Lu et al. | Effects of rotational speed on microstructure and mechanical properties of inertia friction-welded 7005–5083 aluminum alloy joints | |
Sajjadi Nikoo et al. | Microstructure evolution and mechanical properties of friction stir welded joint of ultrafine-grained dissimilar AA2024/AA5083 composite fabricated by accumulative roll bonding | |
Ravi et al. | Influence of tool rotational speed on the mechanical and microstructure properties of friction stir welded Al-B4C MMCs | |
US11549157B2 (en) | Method for modifying surface grain structure of the material and apparatus thereof | |
Jain et al. | Multi-response optimization of friction stir welded reinforced joints of dissimilar aluminum alloys | |
Panwar et al. | Experimental analysis of friction stir welded aviation grade AA8090 joints using Taguchi orthogonal array | |
Al-Allaq et al. | Post-weld heat treatment effects on microstructure, crystal structure, and mechanical properties of donor stir–assisted friction stir welding material of AA6061-T6 alloy | |
Das et al. | Multi-track multi-layer friction stir additive manufacturing of AA6061-T6 alloy | |
Hassan et al. | Investigation on Surface Hardness and Microstructure Evolution in AA 7075-T651 Multi-Layered Laminate Fabricated Through Friction Stir Additive Manufacturing. | |
JP4323296B2 (en) | Method of joining heat-treatable aluminum alloy material and joining material for press forming | |
Yousefi Shivyari et al. | Study on the balance between FSW parameters and heat treatment for an optimized Al2024-T8 joint: microstructural and tensile evaluations | |
Ali | Friction Stir Welding Between Similar and Dissimilar Materials | |
SINDHU | INFLUENCE OF TOOL PIN PROFILE ON MECHANICAL AND METALLURGICAL BEHAVIOR OF FRICTION STIR WELDED AA6061-T6 AND AA2017-T6 TAILORED WELDED BLANKS |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: UNITED TECHNOLOGIES CORPORATION,CONNECTICUT Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:BOEING COMPANY AND BOEING MANAGEMENT COMPANY, THE;REEL/FRAME:017681/0537 Effective date: 20050802 Owner name: UNITED TECHNOLOGIES CORPORATION, CONNECTICUT Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:BOEING COMPANY AND BOEING MANAGEMENT COMPANY, THE;REEL/FRAME:017681/0537 Effective date: 20050802 |
|
AS | Assignment |
Owner name: UNITED TECHNOLOGIES CORPORATION,CONNECTICUT Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:BOEING C OMPANY AND BOEING MANAGEMENT COMPANY, THE;REEL/FRAME:017882/0126 Effective date: 20050802 Owner name: UNITED TECHNOLOGIES CORPORATION, CONNECTICUT Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:BOEING C OMPANY AND BOEING MANAGEMENT COMPANY, THE;REEL/FRAME:017882/0126 Effective date: 20050802 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |
|
AS | Assignment |
Owner name: RUBY ACQUISITION ENTERPRISES CO., CALIFORNIA Free format text: CORRECTIVE ASSIGNMENT TO CORRECT THE ASSIGNEE'S NAME ON ORIGINAL COVER SHEET PREVIOUSLY RECORDED ON REEL 017882 FRAME 0126. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNEE WAS INCORRECTLY RECORDED AS "UNITED TECHNOLOGIES CORPORATION". ASSIGNEE SHOULD BE "RUBY ACQUISITION ENTERPRISES CO.";ASSIGNOR:THE BOEING COMPANY AND BOEING MANAGEMENT COMPANY;REEL/FRAME:030592/0954 Effective date: 20050802 Owner name: PRATT & WHITNEY ROCKETDYNE, INC., CALIFORNIA Free format text: CHANGE OF NAME;ASSIGNOR:RUBY ACQUISITION ENTERPRISES CO.;REEL/FRAME:030593/0055 Effective date: 20050802 |