US20020112788A1 - Ni-Ti-Cu shape memory alloy electrothermal actuator element - Google Patents
Ni-Ti-Cu shape memory alloy electrothermal actuator element Download PDFInfo
- Publication number
- US20020112788A1 US20020112788A1 US10/001,950 US195001A US2002112788A1 US 20020112788 A1 US20020112788 A1 US 20020112788A1 US 195001 A US195001 A US 195001A US 2002112788 A1 US2002112788 A1 US 2002112788A1
- Authority
- US
- United States
- Prior art keywords
- shape
- wire
- actuator element
- memory alloy
- shape memory
- 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
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C19/00—Alloys based on nickel or cobalt
- C22C19/03—Alloys based on nickel or cobalt based on nickel
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
- C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
- C22F1/006—Resulting in heat recoverable alloys with a memory effect
Definitions
- the present invention relates to an Ni—Ti—Cu shape memory alloy electrothermal actuator element.
- a shape memory alloy actuator element is, for example, a linear wire that memorizes its original length.
- the element can repeat a reciprocating movement to cause a prescribed strain at room temperature, and to recover to its original memorized length at a temperature of Af (a finishing temperature of reverse transformation) or higher, under a weight load.
- Ni—Ti shape memory alloy wire has been used as the above-described conventional shape memory alloys.
- this material results some degree of permanent strain after repeating the above-described reciprocating movements many times, thereby causing a certain degree of strain at room temperature that finally leads the material to failure in recovery of its original memorized length at a temperature of Af or higher (hereinafter, this phenomenon is referred to as increasing of a deterioration rate of shape strain recovery).
- the present invention is an Ni—Ti—Cu shape memory alloy electrothermal actuator element that recovers its original shape by electrical heating, having a wire diameter of 0.5 mm or less, which actuator element is composed of an Ni—Ti—Cu shape memory alloy wire which contains 49.0 to 51.0 at % of Ti, and 5.0 to 12.0 at % of Cu, with the balance being made of Ni, wherein the actuator element has a deterioration rate of shape strain recovery of 0.5% or less after repeating desired times of shape recovery movement.
- FIG. 1(A) and FIG. 1(B) each are a schematic view illustrating an electrical heating fatigue testing machine; FIG. 1(A) represents the state when electrical heating, and FIG. 1(B) represents the state when standing to cool.
- FIG. 2 is a schematic view illustrating deterioration rates of shape strain recovery ⁇ and ⁇ , and a shape recovery strain rate ⁇ .
- An Ni—Ti—Cu shape memory alloy electrothermal actuator element that recovers its original shape by electrical heating, having a wire diameter of 0.5 mm or less, comprising an Ni—Ti—Cu shape memory alloy wire which contains 49.0 to 51.0 at % of Ti, and 5.0 to 12.0 at % of Cu, with the balance being made of Ni, wherein the actuator element has a deterioration rate of shape strain recovery of 0.5% or less after repeating desired times of shape recovery movement;
- the actuator element of the present invention composed of an Ni—Ti—Cu shape memory alloy.
- Cu which is one of elements of the alloy, functions for reducing the deterioration rate of shape strain recovery and accelerating the response speed.
- the Cu content is restricted within the range of 5.0 to 12.0 at % because a sufficient effect cannot be attained at the Cu content of less than 5.0 at %, and on the other hand, in case of the Cu content of more than 12.0 at %, the workability of the alloy becomes poor, further the shape recovery strain rate (the difference between the strain rate when heating, and the strain rate when cooling, under a weight load) is reduced.
- Cu content of 6.0 to 8.0 at % is particularly preferable for further increasing the shape recovery strain rate and stable recovering the original shape of the resultant actuator element.
- the Ti content is restricted within the range of 49.0 to 51.0 at % because workability of the arroy becomes poor outside the above-described range of Ti content.
- a heating for shape recovery is conducted by electrical heating, this is because according to the electrical heating, the heating speed is high (a response speed is high), heating operation is simple, the heating speed can be freely controlled by changing the electrothermal current, and the like.
- Ni—Ti—Cu shape memory alloy wire that can be used in the actuator element of the present invention, is used as a liner shape, or another arbitrary shape such as a coiled shape.
- a linear actuator element permits a current density, a temperature distribution, and a stress distribution, when electrical heating, to be uniform, because of the simple shape thereof, thereby allowing the actuator to be widely designed.
- the actuator element of the present invention is used by moving within a narrow strain width (within a narrow temperature hysteresis width) close to an elasticity range, and amplifying the movement.
- a narrow strain width within a narrow temperature hysteresis width
- the amplification of the above-described movement is attained, for example, by the coil shape-actuator element.
- the Ni—Ti—Cu shape memory alloy wire to be used in the present invention can be manufactured in a usual manner by sequentially applying hot-working, cold-drawing, shaping, and shape-memory-heat-treatment, in this order, to an ingot of the Ni—Ti—Cu shape memory alloy. Intermediate annealing can be appropriately applied in the cold-drawing divided into two-steps. A final cold-drawn ratio of 15 to 60% is preferable since the shape recovery strain rate increases in this range of the ratio.
- the temperature for the above-described shape memory heat-treatment is preferably in the range of 400 to 600° C., since a sufficient shape recovery strain rate may not be obtained in some cases when the heat-treatment temperature is too low or too high.
- the deterioration rate of shape strain recovery of the Ni—Ti—Cu alloy actuator element according to any one of the above-described items (1) to (3) is somewhat large at an initial stage of strain.
- the present invention according to the above-described item (4) is an actuator element, wherein the above initial somewhat large deterioration rate is previously alleviated, by applying a pre-treatment, in which the above-described Ni—Ti—Cu shape memory alloy wire is “subjected repeatedly to heating and cooling processes to heat the wire to a temperature of Af or higher, and to cool the wire to a temperature of Mf or lower, under a weight load”, and thereby the deterioration rate of shape strain recovery of the actuator element when it is used is improved to 0.2% or less.
- the actuator element can be heated to a temperature of Af or higher in the above-described pre-treatment, according to an arbitrary method such as electrical heating or heating in a furnace. Since a too high heating temperature damages the wire largely, and reduces the shape recovery strain rate, the preferable temperature is in the range of ⁇ Af+(10 to 50) ⁇ ° C.
- the wire may be non-forcibly cooled (stood to cool) at a temperature of Mf or lower sufficiently, but it may be forced to cool by, for example, blowing air, since the wire has a small diameter.
- the actuator element of the present invention is composed of the Ni—Ti—Cu shape memory alloy wire having a small diameter that can recover its original shape by electrical heating, it has a small deterioration rate of shape strain recovery and also has a rapid response time.
- the Cu content is further controlled to be in the preferable range of 6.0 to 8.0 at %, or wherein the temperature for the shape memory heat-treatment is controlled within the preferable range of 400 to 600° C., or wherein the wire for the actuator element is pre-treated by repeatedly heating/cooling a plurality of times to heat to a temperature of Af or higher and to cool to a temperature of Mf or lower, with applying a weight load corresponding to 10 to 30% of the breaking load, thereby the deterioration rate of shape strain recovery can be further reduced. Accordingly the present invention exhibits industrial remarkable effects.
- Hot-working was applied to an ingot of a Ni—Ti—Cu alloy having a composition defined in the present invention, as shown in Table 1, then a wire of the resultant Ni—Ti—Cu alloy was manufactured by applying cold-drawing, with an appropriate intermediate annealing between the steps of the cold-drawing.
- the diameter of the thus-obtained wire was adjusted to 0.05, 0.20, or 0.50 mm.
- the final cold-drawing ratio was 40% in each cases.
- the wire of a Ni—Ti—Cu alloy was manufactured in the same manner as in Example 1, except that the diameter of the wire was adjusted to 0.80 mm (Sample No. 9).
- the Sample No. 10 wire among the wires obtained in Example 1 and Comparative examples 1 to 3, contained so much Cu that workability was poor, to fail in drawing to a wire with a desired diameter of 0.5 mm.
- the wires (Sample Nos. 1 to 9) other than the Sample No. 10 wire, were applied to the shape memory heat-treatment under the conditions as shown in Table 1, to make the wires memorize their original lengths. Then, the wires were subjected to cycle tests of electrical heating and standing to cool, to determine a deterioration rate of strain ⁇ when electrical heating and a deterioration rate of strain ⁇ when standing to cool, using an electrical heating fatigue testing machine. Further, a shape recovery strain rate ⁇ thereof at initial stage is also determined.
- the above-described deterioration rate ⁇ is the strain rate when electrical heating after 1,000 cycles of the tests
- the above-described deterioration rate ⁇ is a value determined by subtracting the strain rate when standing to cool at the initial stage from the strain rate when standing to cool after 1,000 cycles of the test
- the above-described shape recovery strain rate ⁇ is the strain rate when standing to cool at the initial stage (see FIG. 2). Further, the above-described deterioration rates ⁇ and ⁇ were almost saturated after 1,000 cycles of the test, respectively.
- the above-described electrical heating fatigue testing machine 1 has a construction, in which the both ends of a shape memory alloy wire (actuator element) 2 to be tested are held with pressure connection terminals 3 . As shown in FIGS. 1 (A) and 1 (B), one of the pressure connection terminals 3 is connected to a SUS sleeve shaft 5 through a holder 4 , and tension is applied to the shape memory alloy wire 2 by pulling the sleeve shaft 5 with a bias spring 6 .
- the shape memory alloy wire 2 recovers its originally memorized length, against the tension from the bias spring 6 , as shown in FIG. 1(A), by heating to a temperature of Af or higher.
- the wire is cooled to a temperature of Mf or lower, the mechanical strength of the wire is reduced, and the wire occurs strain (elongated) by yielding to the tension from the bias spring 6 , as shown in FIG. 1(B).
- the shape memory alloy wire 2 is electrically heated with an electrothermal device (not shown).
- the wire of the sample No. 1 that was prepared in the same manner as in Example 1 was subjected to a pre-treatment by repeating ten times of cycles of heating in a furnace at a temperature of 110° C. (Af+25° C.) for five seconds, with applying a weight load of 300 MPa (22% of the breaking load), and then standing to cool at room temperature for five seconds. Then, the electrical heating fatigue test was conducted in the same manner as in the Example 1. As a result, the deterioration rates ⁇ and ⁇ were reduced from 0.45% to 0.1%, and from 0.33% to 0.02%, respectively, showing large improvements of the shape recovery strain rates.
Abstract
Description
- The present invention relates to an Ni—Ti—Cu shape memory alloy electrothermal actuator element.
- A shape memory alloy actuator element is, for example, a linear wire that memorizes its original length. The element can repeat a reciprocating movement to cause a prescribed strain at room temperature, and to recover to its original memorized length at a temperature of Af (a finishing temperature of reverse transformation) or higher, under a weight load.
- Meanwhile, an Ni—Ti shape memory alloy wire has been used as the above-described conventional shape memory alloys. However, there is a problem that this material results some degree of permanent strain after repeating the above-described reciprocating movements many times, thereby causing a certain degree of strain at room temperature that finally leads the material to failure in recovery of its original memorized length at a temperature of Af or higher (hereinafter, this phenomenon is referred to as increasing of a deterioration rate of shape strain recovery).
- To solve the problem described above, alloy wires having a small deterioration rate of shape strain recovery have been sought, and thus an Ni—Ti—Cu shape memory alloy wire has been proposed (JP-A-2-116786 (“JP-A” means unexamined published Japanese patent application)). However, this wire has the problem that its deterioration rate of shape strain recovery cannot be sufficiently reduced, and that its response speed is still slow, since heating of actuator elements using this alloy wire to recover its original shape is operated through water or air as a medium.
- The present invention is an Ni—Ti—Cu shape memory alloy electrothermal actuator element that recovers its original shape by electrical heating, having a wire diameter of 0.5 mm or less, which actuator element is composed of an Ni—Ti—Cu shape memory alloy wire which contains 49.0 to 51.0 at % of Ti, and 5.0 to 12.0 at % of Cu, with the balance being made of Ni, wherein the actuator element has a deterioration rate of shape strain recovery of 0.5% or less after repeating desired times of shape recovery movement.
- Other and further features and advantages of the invention will appear more fully from the following description, take in connection with the accompanying drawings.
- FIG. 1(A) and FIG. 1(B) each are a schematic view illustrating an electrical heating fatigue testing machine; FIG. 1(A) represents the state when electrical heating, and FIG. 1(B) represents the state when standing to cool.
- FIG. 2 is a schematic view illustrating deterioration rates of shape strain recovery α and β, and a shape recovery strain rate γ.
- According to the present invention, there is provided the following means:
- (1) An Ni—Ti—Cu shape memory alloy electrothermal actuator element that recovers its original shape by electrical heating, having a wire diameter of 0.5 mm or less, comprising an Ni—Ti—Cu shape memory alloy wire which contains 49.0 to 51.0 at % of Ti, and 5.0 to 12.0 at % of Cu, with the balance being made of Ni, wherein the actuator element has a deterioration rate of shape strain recovery of 0.5% or less after repeating desired times of shape recovery movement;
- (2) The Ni—Ti—Cu shape memory alloy electrothermal actuator element according to item (1), wherein the Cu content of the Ni—Ti—Cu shape memory alloy is 6.0 to 8.0 at %;
- (3) The Ni—Ti—Cu shape memory alloy electrothermal actuator element according to item (1) or (2), wherein the Ni—Ti—Cu shape memory alloy wire is subjected to a shape memory heat-treatment at a temperature in the range from 400 to 600° C.; and
- (4) An Ni—Ti—Cu shape memory alloy electrothermal actuator element, wherein the wire in the actuator element according to any one of items (1) to (3) is subjected to repeating cycles of heating to a temperature of Af or higher with applying a weight load corresponding to 10 to 30% of a breaking load of the wire, and cooling to a temperature of Mf (a finishing temperature of Martensitic transformation) or lower, and wherein the deterioration rate of shape strain recovery after repeating desired times of shape recovery movement is 0.2% or less.
- The actuator element of the present invention composed of an Ni—Ti—Cu shape memory alloy. Cu, which is one of elements of the alloy, functions for reducing the deterioration rate of shape strain recovery and accelerating the response speed.
- The Cu content is restricted within the range of 5.0 to 12.0 at % because a sufficient effect cannot be attained at the Cu content of less than 5.0 at %, and on the other hand, in case of the Cu content of more than 12.0 at %, the workability of the alloy becomes poor, further the shape recovery strain rate (the difference between the strain rate when heating, and the strain rate when cooling, under a weight load) is reduced. Cu content of 6.0 to 8.0 at % is particularly preferable for further increasing the shape recovery strain rate and stable recovering the original shape of the resultant actuator element.
- The Ti content is restricted within the range of 49.0 to 51.0 at % because workability of the arroy becomes poor outside the above-described range of Ti content.
- In the present invention, a heating for shape recovery is conducted by electrical heating, this is because according to the electrical heating, the heating speed is high (a response speed is high), heating operation is simple, the heating speed can be freely controlled by changing the electrothermal current, and the like.
- On the other hand, in the electrical heating, the temperature distribution tends to be ununiform because heating rate is so fast. Accordingly, the fatigue of the wire is easy to occur. However, this defect was solved in the present invention by thinning down the wire diameter to 0.5 mm or less. When the wire diameter is thinned down to 0.5 mm or less, it permits the deterioration rate of shape strain recovery to be reduced and the response time to be shortened since the heating and cooling rates of the shape memory alloy wire are increased.
- The Ni—Ti—Cu shape memory alloy wire that can be used in the actuator element of the present invention, is used as a liner shape, or another arbitrary shape such as a coiled shape. A linear actuator element permits a current density, a temperature distribution, and a stress distribution, when electrical heating, to be uniform, because of the simple shape thereof, thereby allowing the actuator to be widely designed.
- The actuator element of the present invention is used by moving within a narrow strain width (within a narrow temperature hysteresis width) close to an elasticity range, and amplifying the movement. By that, the deterioration rate of shape strain recovery can be further reduced, the lifetime of the actuator element can be prolonged, and reproducibility of the movement can be improved. The amplification of the above-described movement is attained, for example, by the coil shape-actuator element.
- The Ni—Ti—Cu shape memory alloy wire to be used in the present invention can be manufactured in a usual manner by sequentially applying hot-working, cold-drawing, shaping, and shape-memory-heat-treatment, in this order, to an ingot of the Ni—Ti—Cu shape memory alloy. Intermediate annealing can be appropriately applied in the cold-drawing divided into two-steps. A final cold-drawn ratio of 15 to 60% is preferable since the shape recovery strain rate increases in this range of the ratio. The temperature for the above-described shape memory heat-treatment is preferably in the range of 400 to 600° C., since a sufficient shape recovery strain rate may not be obtained in some cases when the heat-treatment temperature is too low or too high.
- The deterioration rate of shape strain recovery of the Ni—Ti—Cu alloy actuator element according to any one of the above-described items (1) to (3) is somewhat large at an initial stage of strain. The present invention according to the above-described item (4) is an actuator element, wherein the above initial somewhat large deterioration rate is previously alleviated, by applying a pre-treatment, in which the above-described Ni—Ti—Cu shape memory alloy wire is “subjected repeatedly to heating and cooling processes to heat the wire to a temperature of Af or higher, and to cool the wire to a temperature of Mf or lower, under a weight load”, and thereby the deterioration rate of shape strain recovery of the actuator element when it is used is improved to 0.2% or less.
- When the weight load in the above-described pre-treatment is so large that the wire receives a plastic deformation, the wire is largely damaged, and the shape recovery strain rate is reduced. On the other hand, when the weight load is too small, a sufficient effect by the pre-treatment cannot be obtained. Accordingly, it is preferable to apply the above-described weight load corresponding to 10 to 30%, particularly preferably 15 to 25%, of the wire's breaking load.
- The actuator element can be heated to a temperature of Af or higher in the above-described pre-treatment, according to an arbitrary method such as electrical heating or heating in a furnace. Since a too high heating temperature damages the wire largely, and reduces the shape recovery strain rate, the preferable temperature is in the range of {Af+(10 to 50)}° C. The wire may be non-forcibly cooled (stood to cool) at a temperature of Mf or lower sufficiently, but it may be forced to cool by, for example, blowing air, since the wire has a small diameter.
- Since the actuator element of the present invention is composed of the Ni—Ti—Cu shape memory alloy wire having a small diameter that can recover its original shape by electrical heating, it has a small deterioration rate of shape strain recovery and also has a rapid response time. According to the actuator element of a preferable embodiment of the present invention, wherein the Cu content is further controlled to be in the preferable range of 6.0 to 8.0 at %, or wherein the temperature for the shape memory heat-treatment is controlled within the preferable range of 400 to 600° C., or wherein the wire for the actuator element is pre-treated by repeatedly heating/cooling a plurality of times to heat to a temperature of Af or higher and to cool to a temperature of Mf or lower, with applying a weight load corresponding to 10 to 30% of the breaking load, thereby the deterioration rate of shape strain recovery can be further reduced. Accordingly the present invention exhibits industrial remarkable effects.
- The present invention will be explained in more detail referring to the following examples, but the invention is not limited thereto.
- Hot-working was applied to an ingot of a Ni—Ti—Cu alloy having a composition defined in the present invention, as shown in Table 1, then a wire of the resultant Ni—Ti—Cu alloy was manufactured by applying cold-drawing, with an appropriate intermediate annealing between the steps of the cold-drawing. The diameter of the thus-obtained wire was adjusted to 0.05, 0.20, or 0.50 mm. The final cold-drawing ratio was 40% in each cases.
- The wires of Ni—Ti—Cu alloys were manufactured in the same manner as in Example 1, except that ingots of Ni—Ti—Cu alloys with compositions outside the definition in the present invention, as shown in Table 1, were used, respectively (Sample Nos. 8 and 10).
- The wire of a Ni—Ti—Cu alloy was manufactured in the same manner as in Example 1, except that the diameter of the wire was adjusted to 0.80 mm (Sample No. 9).
- The wires of Ni—Ti alloys were manufactured in the same manner as in Example 1, except that ingots of Ni—Ti alloys with compositions, as shown in Table 1, were used, respectively (Sample Nos. 6 and 7).
- The Sample No. 10 wire, among the wires obtained in Example 1 and Comparative examples 1 to 3, contained so much Cu that workability was poor, to fail in drawing to a wire with a desired diameter of 0.5 mm.
- The wires (Sample Nos. 1 to 9) other than the Sample No. 10 wire, were applied to the shape memory heat-treatment under the conditions as shown in Table 1, to make the wires memorize their original lengths. Then, the wires were subjected to cycle tests of electrical heating and standing to cool, to determine a deterioration rate of strain α when electrical heating and a deterioration rate of strain β when standing to cool, using an electrical heating fatigue testing machine. Further, a shape recovery strain rate γ thereof at initial stage is also determined.
- The above-described deterioration rate α is the strain rate when electrical heating after 1,000 cycles of the tests, and the above-described deterioration rate β is a value determined by subtracting the strain rate when standing to cool at the initial stage from the strain rate when standing to cool after 1,000 cycles of the test, and the above-described shape recovery strain rate γ is the strain rate when standing to cool at the initial stage (see FIG. 2). Further, the above-described deterioration rates α and β were almost saturated after 1,000 cycles of the test, respectively.
- The above-described electrical heating fatigue testing machine1 has a construction, in which the both ends of a shape memory alloy wire (actuator element) 2 to be tested are held with
pressure connection terminals 3. As shown in FIGS. 1(A) and 1(B), one of thepressure connection terminals 3 is connected to aSUS sleeve shaft 5 through aholder 4, and tension is applied to the shapememory alloy wire 2 by pulling thesleeve shaft 5 with abias spring 6. - The shape
memory alloy wire 2 recovers its originally memorized length, against the tension from thebias spring 6, as shown in FIG. 1(A), by heating to a temperature of Af or higher. When the wire is cooled to a temperature of Mf or lower, the mechanical strength of the wire is reduced, and the wire occurs strain (elongated) by yielding to the tension from thebias spring 6, as shown in FIG. 1(B). The shapememory alloy wire 2 is electrically heated with an electrothermal device (not shown). - The test results are shown in Table 2, together with the cycle test conditions.
TABLE 1 Shape memory heat- Wire treatment condition Sample Alloy Ti Cu diameter Temperature Time Classification No. No. (at %) (at %) Ni (mm) (° C.) (minute) Example 1 a 50.5 7.0 Balance 0.20 500 0.5 according to 2 b 50.5 9.0 Balance 0.05 500 0.5 this 3 b 50.5 9.0 Balance 0.20 500 0.5 invention 4 b 50.5 9.0 Balance 0.50 500 0.5 5 c 50.5 11.0 Balance 0.20 500 0.5 Comparative 6 f 50.0 0.0 Balance 0.05 500 0.5 example 7 f 50.0 0.0 Balance 0.20 500 0.5 8 g 50.5 3.0 Balance 0.20 500 0.5 9 b 50.5 9.0 Balance 0.80 500 0.5 10 h 50.5 13.0 Balance Impossible to work to a wire diameter of 0.5 mm. -
TABLE 2 Deterioration rate Cycle test condition of shape recovery Electro- strain Shape thermal Time for When When recovery Weight current standing heated stood strain Sample Alloy load (A) × time to cool electrically to cool rate γ Classification No. No. (MPa) (second) (second) α (%) β (%) (%) Example 1 a 175 0.50 × 5 15 0.45 0.33 4.02 according to 2 b 275 0.10 × 5 5 0.09 0.01 4.23 this invention 3 b 175 0.50 × 5 15 0.13 0.02 3.78 4 b 175 2.00 × 10 25 0.35 0.43 4.15 5 c 175 0.50 × 5 15 0.06 0.03 3.51 Comparative 6 f 275 0.10 × 5 5 2.27 0.80 4.86 example 7 f 175 0.50 × 5 15 2.52 2.14 4.32 8 g 175 0.50 × 5 15 0.89 0.71 4.20 9 b 175 3.00 × 20 60 0.76 0.53 3.91 - As is apparent from the results in Table 2, the deterioration rates of shape strain recovery α and β were as small as 0.5% or less in the sample Nos. 1 to 5 of examples according to the present invention, even after repeating 1,000 times of the shape recovery movement. In other words, the wires could almost recover their originally memorized length after 1,000 cycles of the test, indicating good shape recovery abilities. The sample No. 1 had a larger shape recovery strain rate γ, as compared with the sample Nos. 3 and 5, since the Cu content was optimum in the sample No. 1.
- On the contrary, both the sample Nos. 6 and 7 were poorly large in the deterioration rates of shape strain recovery since Cu was not contained in these samples. The deterioration rates of shape strain recovery α and β each were poorly large in sample Nos. 8 and 9, respectively, because the Cu content in the sample No. 8 was too small and the wire of the sample No. 9 was too large in diameter.
- The wire of the sample No. 1 that was prepared in the same manner as in Example 1 was subjected to a pre-treatment by repeating ten times of cycles of heating in a furnace at a temperature of 110° C. (Af+25° C.) for five seconds, with applying a weight load of 300 MPa (22% of the breaking load), and then standing to cool at room temperature for five seconds. Then, the electrical heating fatigue test was conducted in the same manner as in the Example 1. As a result, the deterioration rates α and β were reduced from 0.45% to 0.1%, and from 0.33% to 0.02%, respectively, showing large improvements of the shape recovery strain rates.
- The time required for deformation when standing to cool (the response time) in the electrical heating fatigue test was determined with respect to the sample Nos. 2 and 3 (Ni—Ti—Cu shape memory alloys) and the sample Nos. 6 and 7 (Ni—Ti shape memory alloys) that were prepared in the same manner as in Example 1. The results are shown in Table 3.
TABLE 3 Wire Deformation Sample Alloy diameter time Classification No. No. (mm) (second) Example 2 b 0.05 0.4 according to 3 b 0.20 11.9 this invention Comparative 6 f 0.05 0.6 example 7 f 0.20 14.1 - As is apparent from the results in Table 3, the response speeds of the samples according to the present invention (the Sample Nos. 2 and 3) were much faster than those of the samples of the comparative examples (the Samples Nos. 6 and 7) in case of both 0.05 mm and 0.20 mm of the wire diameter. This is because the temperature hysteresis was quite small in the examples according to the present invention, as a result of adding Cu.
- Having described our invention as related to the present embodiments, it is our intention that the invention not be limited by any of the details of the description, unless otherwise specified, but rather be construed broadly within its spirit and scope as set out in the accompanying claims.
Claims (8)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2000375117A JP3956613B2 (en) | 2000-12-08 | 2000-12-08 | NiTiCu shape memory alloy conducting actuator element |
JP2000-375117 | 2000-12-08 |
Publications (1)
Publication Number | Publication Date |
---|---|
US20020112788A1 true US20020112788A1 (en) | 2002-08-22 |
Family
ID=18844179
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/001,950 Abandoned US20020112788A1 (en) | 2000-12-08 | 2001-10-22 | Ni-Ti-Cu shape memory alloy electrothermal actuator element |
Country Status (2)
Country | Link |
---|---|
US (1) | US20020112788A1 (en) |
JP (1) | JP3956613B2 (en) |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20070034818A1 (en) * | 2003-04-15 | 2007-02-15 | Board Of Trustees Operating Michigan State University | Prestrained thin-film shape memory actuator using polymeric substrates |
US20110096421A1 (en) * | 2005-08-11 | 2011-04-28 | Saori Hirata | Drive Device, Lens Barrel, Imaging Device, Lens Drive Method and Method of Producing Shape Memory Alloy |
WO2011053737A2 (en) | 2009-11-02 | 2011-05-05 | Saes Smart Materials | Ni-Ti SEMI-FINISHED PRODUCTS AND RELATED METHODS |
CN103160707A (en) * | 2011-12-13 | 2013-06-19 | 西安赛特金属材料开发有限公司 | Titanium-nickel-based shape memory alloy material used for fire-fighting automatic temperature control element |
EP3343078A1 (en) * | 2016-12-29 | 2018-07-04 | L&P Property Management Company | Valve with shape memory alloy wire |
CN108262367A (en) * | 2018-01-22 | 2018-07-10 | 哈尔滨工业大学 | A kind of preparation method with the NiTi alloy micrometer fibers for playing hot property |
CN113215421A (en) * | 2021-04-06 | 2021-08-06 | 华南理工大学 | Low-stress driven high-elasticity all-martensite nickel-titanium alloy and preparation method thereof |
US11808374B2 (en) | 2020-12-30 | 2023-11-07 | Leggett & Platt Canada Co. | Fluid management system |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6945045B2 (en) | 2001-10-01 | 2005-09-20 | Minolta Co., Ltd. | Driving apparatus |
JP4633387B2 (en) * | 2004-05-26 | 2011-02-16 | 学校法人東京理科大学 | Shape memory alloy member, shape memory method thereof, and actuator for flow rate control |
JP5050337B2 (en) * | 2004-12-06 | 2012-10-17 | コニカミノルタアドバンストレイヤー株式会社 | Drive device |
CN101982657B (en) * | 2010-11-19 | 2012-01-25 | 哈尔滨工业大学 | Square sleeve-type actuator made of shape memory alloy for increasing displacement |
CN104060126A (en) * | 2014-07-01 | 2014-09-24 | 张家港市佳晟机械有限公司 | Nickel-titanium system shape memory alloy |
CN109136806B (en) * | 2018-11-09 | 2020-12-25 | 中国石油大学(华东) | Preparation method of NiTi monocrystal in solid state by cyclic heat treatment |
CN111850437B (en) * | 2020-07-29 | 2021-09-24 | 无锡东创智能材料科技有限公司 | Nickel-titanium shape memory alloy wire and preparation method and application thereof |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5718576A (en) * | 1996-04-19 | 1998-02-17 | Minnesota Mining & Manufacturing Co. | Orthodontic attachment device and pin |
US5782896A (en) * | 1997-01-29 | 1998-07-21 | Light Sciences Limited Partnership | Use of a shape memory alloy to modify the disposition of a device within an implantable medical probe |
-
2000
- 2000-12-08 JP JP2000375117A patent/JP3956613B2/en not_active Expired - Fee Related
-
2001
- 2001-10-22 US US10/001,950 patent/US20020112788A1/en not_active Abandoned
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5718576A (en) * | 1996-04-19 | 1998-02-17 | Minnesota Mining & Manufacturing Co. | Orthodontic attachment device and pin |
US5782896A (en) * | 1997-01-29 | 1998-07-21 | Light Sciences Limited Partnership | Use of a shape memory alloy to modify the disposition of a device within an implantable medical probe |
Cited By (21)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7690621B2 (en) * | 2003-04-15 | 2010-04-06 | Board Of Trustees Operating Michigan State University | Prestrained thin-film shape memory actuator using polymeric substrates |
US20070034818A1 (en) * | 2003-04-15 | 2007-02-15 | Board Of Trustees Operating Michigan State University | Prestrained thin-film shape memory actuator using polymeric substrates |
US20110226392A1 (en) * | 2005-08-11 | 2011-09-22 | Konica Minolta Opto, Inc. | Drive device, lens barrel, image pickup apparatus, lens drive method and method of producing shape memory alloy |
US20110096421A1 (en) * | 2005-08-11 | 2011-04-28 | Saori Hirata | Drive Device, Lens Barrel, Imaging Device, Lens Drive Method and Method of Producing Shape Memory Alloy |
US8000027B2 (en) * | 2005-08-11 | 2011-08-16 | Konica Minolta Opto, Inc. | Drive device, lens barrel, image pickup apparatus, lens drive method and method of producing shape memory alloy |
EP2496724A4 (en) * | 2009-11-02 | 2013-04-17 | Saes Smart Materials | Ni-Ti SEMI-FINISHED PRODUCTS AND RELATED METHODS |
KR101334287B1 (en) | 2009-11-02 | 2013-11-29 | 사에스 스마트 머티리얼즈 | Ni-Ti SEMI-FINISHED PRODUCTS AND RELATED METHODS |
US8152941B2 (en) | 2009-11-02 | 2012-04-10 | Saes Smart Materials | Ni-Ti semi-finished products and related methods |
EP2496724A2 (en) * | 2009-11-02 | 2012-09-12 | SAES Smart Materials | Ni-Ti SEMI-FINISHED PRODUCTS AND RELATED METHODS |
EP2500443A1 (en) * | 2009-11-02 | 2012-09-19 | SAES Smart Materials | NI-TI semi-finished products and related methods |
WO2011053737A2 (en) | 2009-11-02 | 2011-05-05 | Saes Smart Materials | Ni-Ti SEMI-FINISHED PRODUCTS AND RELATED METHODS |
US9315880B2 (en) | 2009-11-02 | 2016-04-19 | Saes Smart Materials | Ni-Ti semi-finished products and related methods |
WO2011053737A3 (en) * | 2009-11-02 | 2011-09-29 | Saes Smart Materials | Ni-Ti SEMI-FINISHED PRODUCTS AND RELATED METHODS |
KR101334290B1 (en) | 2009-11-02 | 2013-11-29 | 사에스 스마트 머티리얼즈 | Ni-Ti SEMI-FINISHED PRODUCTS AND RELATED METHODS |
CN103160707A (en) * | 2011-12-13 | 2013-06-19 | 西安赛特金属材料开发有限公司 | Titanium-nickel-based shape memory alloy material used for fire-fighting automatic temperature control element |
EP3343078A1 (en) * | 2016-12-29 | 2018-07-04 | L&P Property Management Company | Valve with shape memory alloy wire |
WO2018122387A1 (en) * | 2016-12-29 | 2018-07-05 | L&P Property Management Company | Valve with shape memory alloy wire |
US11028937B2 (en) | 2016-12-29 | 2021-06-08 | L&P Property Management Company | Valve with shape memory alloy wire |
CN108262367A (en) * | 2018-01-22 | 2018-07-10 | 哈尔滨工业大学 | A kind of preparation method with the NiTi alloy micrometer fibers for playing hot property |
US11808374B2 (en) | 2020-12-30 | 2023-11-07 | Leggett & Platt Canada Co. | Fluid management system |
CN113215421A (en) * | 2021-04-06 | 2021-08-06 | 华南理工大学 | Low-stress driven high-elasticity all-martensite nickel-titanium alloy and preparation method thereof |
Also Published As
Publication number | Publication date |
---|---|
JP2002180951A (en) | 2002-06-26 |
JP3956613B2 (en) | 2007-08-08 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US20020112788A1 (en) | Ni-Ti-Cu shape memory alloy electrothermal actuator element | |
KR101004051B1 (en) | Iron-based alloy having shape-memory property and superelasticity and method for manufacture thereof | |
JPS60128252A (en) | Shape memory alloy | |
US3948688A (en) | Martensitic alloy conditioning | |
JPWO2004085685A1 (en) | Manufacturing method of high strength spring | |
US9476113B1 (en) | Thermomechanical methodology for stabilizing shape memory alloy (SMA) response | |
US5863494A (en) | Iron-nickel superalloy of the type in 706 | |
CA2184850C (en) | A high temperature process for making an iron-nickel superalloy 706 body | |
Lagoudas et al. | Thermomechanical transformation fatigue of SMA actuators | |
JP4558183B2 (en) | Manufacturing method of valve spring | |
CN102787285B (en) | Heat treatment method for obtaining two-way shape memory effect of SMA (Shape Memory Alloy) material | |
SHIBATA et al. | Serration of Fe-Ni austenitic steels at very low temperatures and its computer simulation | |
JP3555814B2 (en) | Coil spring manufacturing method | |
JP3634418B2 (en) | Coil spring manufacturing method and high toughness / high tensile strength coil spring | |
JP2007009300A (en) | Method for manufacturing cold-coiled wire rod for spring | |
US20090320972A1 (en) | Method for tempering an aluminum alloy | |
CN108118194B (en) | Preparation method of Fe-Co-based magnetostrictive alloy wire | |
JPS61227141A (en) | Niti shape memory alloy wire | |
US7253219B2 (en) | Functional composite material using shape memory alloy and production method therefor | |
US4936925A (en) | Method for producing alloy of low thermal expansion | |
JP3755032B2 (en) | SHAPE MEMORY ALLOY WIRE FOR USE IN DIRECTION REQUIRED AND METHOD FOR MANUFACTURING THE SAME | |
JPH031459A (en) | Wiring connector using shape memory alloy | |
JPS63127225A (en) | Spectacles parts | |
JPS58217834A (en) | Superelastic spring | |
JPH0238547A (en) | Manufacture of ti-ni shape memory alloy |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: FURUKAWA ELECTRIC CO., LTD., THE, JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:TANAKA, TOYONOBU;HORIKAWA, HIROSHI;IWASAKI, KEIZO;AND OTHERS;REEL/FRAME:012571/0096;SIGNING DATES FROM 20011108 TO 20011112 Owner name: FURUKAWA TECHNO MATERIAL CO., LTD., THE, JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:TANAKA, TOYONOBU;HORIKAWA, HIROSHI;IWASAKI, KEIZO;AND OTHERS;REEL/FRAME:012571/0096;SIGNING DATES FROM 20011108 TO 20011112 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |