CN104233130A - Process for improving thermal fatigue property of copper-zinc-aluminum shape memory alloy - Google Patents
Process for improving thermal fatigue property of copper-zinc-aluminum shape memory alloy Download PDFInfo
- Publication number
- CN104233130A CN104233130A CN201310230572.4A CN201310230572A CN104233130A CN 104233130 A CN104233130 A CN 104233130A CN 201310230572 A CN201310230572 A CN 201310230572A CN 104233130 A CN104233130 A CN 104233130A
- Authority
- CN
- China
- Prior art keywords
- copper
- thermal fatigue
- zinc
- room temperature
- sample
- 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.)
- Pending
Links
Landscapes
- Investigating And Analyzing Materials By Characteristic Methods (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
- Sampling And Sample Adjustment (AREA)
Abstract
The invention provides a process for improving a thermal fatigue property of a copper-zinc-aluminum shape memory alloy, and belongs to the technical field of preparation of copper-based shape memory alloys. The process is characterized in that: raw materials include 25-25.5 wt% of Zn, 3.5-4 wt% of Al, 0.8-1.0 wt% of Ni and 0.2-1.0 wt% of composite rear earth, with the balance being copper, and are weighed according to the ratio and smelted in a medium-frequency induction smelting furnace. The process also includes: a step of heating to 1280-1300 DEG C after the materials are fully melt; a step of casting to obtain cast ingots having a diameter of 80 mm and a length of 150 mm; a step of annealing, namely a step of heating to 820 DEG C, maintaining the temperature for 24 h, and performing furnace cooling; a step of removing a dezincification layer having a thickness of 2-3 mm on the surface; a step of forging a cast ingot into a bar having a size of 35*35 mm after the cast ingot is maintained at a temperature of 820 DEG C for 30 min; and a step of performing thermal treatment with two-level ageing. A sample prepared by the process is subjected to mechanical property tests and thermal fatigue property tests.
Description
Technical field
The invention belongs to copper-based shape memory alloy preparing technical field, refer in particular to a kind of processing method improving copper-zinc-aluminum shape memory alloy thermal fatigue property.
Background technology
Copper-based shape memory alloy is one of the new function material of two active research and exploitations during the last ten years both at home and abroad in the past, finds that there is good shape memory effect at the tens of kinds of copper base alloys such as Cu-Zn, Cu-Zn-Al, Cu-Sn, Cu-Al-Ni, Cu-Al-Be, Cu-Sn-Si, Cu-Zn-Ga at present.What in copper-based shape memory alloy, most study had also been applied is Cu-Zn-Al and Cu-Al-Ni alloy.CuZnAl shape memory alloy is as one of alloy with practical value of most in copper-based memory alloy, and due to its handling ease, plasticity is high, and memory performance is good, cheap, is more and more subject to people's attention.Thermo-elasticity inversion temperature can up to 400 DEG C under quenching conditions for the novel high heat resistant copper-based shape memory alloy of current research, and the modified version of this alloy is used in military project research at present.The condition producing phase transformation wide transformation hysteresis according to copper-based shape memory alloy have developed wide transformation hysteresis electrostatic storage tube joint, is solving electrostatic storage tube joint preparation technology's problem and application problem at present.But CuZnAl shape memory alloy also exists the defect such as coarse grains, martensite stabilization, wanting broadened application scope needs the subject matter solved to be improve plasticity, improves shape memory effect to aspects such as the stability of thermal cycling and repeated deformation.
The present invention develops a kind of processing method improving copper-zinc-aluminum shape memory alloy thermal fatigue property.By Metamorphism treatment, anneal, forge and the series of process means such as subsequent heat treatment, significantly improve copper-zinc-aluminum shape memory alloy thermal fatigue property.
Summary of the invention
The present invention develops a kind of processing method that can improve copper-zinc-aluminum shape memory alloy thermal fatigue property, it is characterized by: with electrolytic copper, No. 0, zinc ingot metal, No. A00, industrial aluminium ingot, 1# electrolytic nickel, composite rare-earth modifier (wherein Nd 10 ~ 15wt%, La 10 ~ 15 wt%, Y 8 ~ 12wt%, Ce 8 ~ 12wt%, Tb 5 ~ 8 wt%, Gd 5 ~ 8 wt%, Pr+Sc+Eu+Ho+Er+Tm+Lu for 10 ~ 20wt%, Zr 3 ~ 6wt%, Ti 2 ~ 5wt%, B 2 ~ 5wt%, Yu Weitong) be raw material.Composition weigh in the ratio that Zn25-25.5wt%, Al3.5-4wt%, Ni0.8-1.0wt%, composite rare-earth modifier 0.2-1.0wt%, surplus are copper after melting in medium frequency induction melting furnace.Melting technology is: first add preheated electrolytic copper, electrolytic nickel, aluminium ingot, after add zinc ingot metal and composite rare-earth modifier, to add in fusion process a small amount of borax cover, add-on is the 0.15wt% of molten metal.After material all melts, be warming up to 1280 DEG C-1300 DEG C, pour into the ingot casting that diameter is φ 80 × 150mm.Anneal is heated to 820 DEG C of insulations furnace cooling after 24 hours, and then the dezincify layer of surperficial 2-3mm is removed in turning, then ingot casting is forged into the bar of 45 × 45mm after 840 DEG C of insulation half an hour.Finally carry out the thermal treatment of two-stage timeliness, namely 820-840 DEG C of insulation is quenched in room temperature machine oil for 1 hour, takes out air cooling to room temperature after being then incubated 0.5 hour in preprepared 100 DEG C of boiling water, then takes out air cooling to room temperature be incubated 0.5 hour in 50 DEG C of water after.The thermal fatigue property of copper-zinc-aluminum shape memory alloy prepared by the method is significantly improved.
Bar after thermal treatment is processed into national standard coupon, room temperature tensile Mechanics Performance Testing is carried out on WE-10 type fluid pressure type tensile testing machine, memorial alloy tensile strength 695.5MPa is recorded, elongation 9.5%, Brinell hardness 186HB after this processing method process.Sample on bar, go out thermal fatigue sample by linear cutter, thermal fatigue specimen size is long 40 mm, wide 10 mm, high 5mm, sample top with v-notch, as shown in Figure 1.Resistance furnace heating is adopted to carry out thermal fatigue test from constraint thermal fatigue tester.Plate tensile sample is installed on four sides of cube jig, ensures that the heating of every block sample is consistent with cool position, and by the upper and lower vertical movement of transmission mechanism, thus the automatization reaching sample heating and cooling completes.Automatic control when employing is established, thermocouple measurement control temperature, sample carries out the thermal cycling of heating Yu cooling between room temperature 20 DEG C to 300 DEG C, 400 DEG C, 500 DEG C, adopts counter to carry out Auto-counting, adjust and keep furnace temperature accurate, water temperature 20 DEG C (flowing tap water).Rapid heating sample, heating, cooling are once as a circulation, and each circulating-heating time is 120s, and entering the water cooling time is 15s, until predetermined cycle index.Often circulate 1000 times, take off sample, surface film oxide is removed in polishing, surface measurements crack length.
accompanying drawing explanation
Fig. 1 thermal fatigue specimen size (unit mm)
The different ceiling temperature of Fig. 2 is on the impact of copper-zinc-aluminum shape memory alloy thermal fatigue property
The thermal cycling of heating Yu cooling is carried out between 1-20 DEG C to 300 DEG C;
The thermal cycling of heating Yu cooling is carried out between 2-20 DEG C to 400 DEG C;
The thermal cycling of heating Yu cooling is carried out between 3-20 DEG C to 500 DEG C.
embodiment
embodiment 1
With electrolytic copper, No. 0, zinc ingot metal, No. A00, industrial aluminium ingot, 1# electrolytic nickel, composite rare-earth modifier for raw material.Composition weigh in the ratio that Zn25-25.5wt%, Al3.5-4wt%, Ni0.8-1.0wt%, composite rare-earth modifier 0.6-0.8wt%, surplus are copper after melting in medium frequency induction melting furnace.Melting technology is: first add preheated electrolytic copper, electrolytic nickel, aluminium ingot, after add zinc ingot metal and composite rare-earth modifier, to add in fusion process a small amount of borax cover, add-on is the 0.15wt% of molten metal.After material all melts, be warming up to 1280 DEG C-1300 DEG C, pour into the ingot casting that diameter is φ 80 × 150mm.Anneal is heated to 820 DEG C of insulations furnace cooling after 24 hours, and then the dezincify layer of surperficial 2-3mm is removed in turning, then ingot casting is forged into the bar of 45 × 45mm after 840 DEG C of insulation half an hour.Finally carry out the thermal treatment of two-stage timeliness, namely 820-840 DEG C of insulation is quenched in room temperature machine oil for 1 hour, takes out air cooling to room temperature after being then incubated 0.5 hour in preprepared 100 DEG C of boiling water, then takes out air cooling to room temperature be incubated 0.5 hour in 50 DEG C of water after.Bar after thermal treatment is processed into national standard coupon, room temperature tensile Mechanics Performance Testing is carried out on WE-10 type fluid pressure type tensile testing machine, memorial alloy tensile strength 695.5MPa is recorded, elongation 9.5%, Brinell hardness 186HB after this processing method process.Sample on bar, go out thermal fatigue sample by linear cutter, thermal fatigue specimen size is long 40 mm, wide 10 mm, high 5mm, sample top with v-notch, as shown in Figure 1.Resistance furnace heating is adopted to carry out thermal fatigue test from constraint thermal fatigue tester.Plate tensile sample is installed on four sides of cube jig, ensures that the heating of every block sample is consistent with cool position, and by the upper and lower vertical movement of transmission mechanism, thus the automatization reaching sample heating and cooling completes.Automatic control when employing is established, thermocouple measurement control temperature, sample carries out the thermal cycling of heating Yu cooling between room temperature 20 DEG C to 300 DEG C, adopts counter to carry out Auto-counting, adjust and keeps furnace temperature accurately, water temperature 20 DEG C (flowing tap water).Rapid heating sample, heating, cooling are once as a circulation, and each circulating-heating time is 120s, and entering the water cooling time is 15s, until predetermined cycle index.Often circulate 1000 times, take off sample, surface film oxide is removed in polishing, and surface measurements crack length, sample marking is 3, and thermal fatigue property is shown in Fig. 2.
embodiment 2
With electrolytic copper, No. 0, zinc ingot metal, No. A00, industrial aluminium ingot, 1# electrolytic nickel, composite rare-earth modifier for raw material.Composition weigh in the ratio that Zn25-25.5wt%, Al3.5-4wt%, Ni0.8-1.0wt%, composite rare-earth modifier 0.6-0.8wt%, surplus are copper after melting in medium frequency induction melting furnace.Melting technology is: first add preheated electrolytic copper, electrolytic nickel, aluminium ingot, after add zinc ingot metal and composite rare-earth modifier, to add in fusion process a small amount of borax cover, add-on is the 0.15wt% of molten metal.After material all melts, be warming up to 1280 DEG C-1300 DEG C, pour into the ingot casting that diameter is φ 80 × 150mm.Anneal is heated to 820 DEG C of insulations furnace cooling after 24 hours, and then the dezincify layer of surperficial 2-3mm is removed in turning, then ingot casting is forged into the bar of 45 × 45mm after 840 DEG C of insulation half an hour.Finally carry out the thermal treatment of two-stage timeliness, namely 820-840 DEG C of insulation is quenched in room temperature machine oil for 1 hour, takes out air cooling to room temperature after being then incubated 0.5 hour in preprepared 100 DEG C of boiling water, then takes out air cooling to room temperature be incubated 0.5 hour in 50 DEG C of water after.Bar after thermal treatment is processed into national standard coupon, room temperature tensile Mechanics Performance Testing is carried out on WE-10 type fluid pressure type tensile testing machine, memorial alloy tensile strength 695.5MPa is recorded, elongation 9.5%, Brinell hardness 186HB after this processing method process.Sample on bar, go out thermal fatigue sample by linear cutter, thermal fatigue specimen size is long 40 mm, wide 10 mm, high 5mm, sample top with v-notch, as shown in Figure 1.Resistance furnace heating is adopted to carry out thermal fatigue test from constraint thermal fatigue tester.Plate tensile sample is installed on four sides of cube jig, ensures that the heating of every block sample is consistent with cool position, and by the upper and lower vertical movement of transmission mechanism, thus the automatization reaching sample heating and cooling completes.Automatic control when employing is established, thermocouple measurement control temperature, sample carries out the thermal cycling of heating Yu cooling between room temperature 20 DEG C to 400 DEG C, adopts counter to carry out Auto-counting, adjust and keeps furnace temperature accurately, water temperature 20 DEG C (flowing tap water).Rapid heating sample, heating, cooling are once as a circulation, and each circulating-heating time is 120s, and entering the water cooling time is 15s, until predetermined cycle index.Often circulate 1000 times, take off sample, surface film oxide is removed in polishing, and surface measurements crack length, sample marking is 2, and thermal fatigue property is shown in Fig. 2.
embodiment 3
With electrolytic copper, No. 0, zinc ingot metal, No. A00, industrial aluminium ingot, 1# electrolytic nickel, composite rare-earth modifier for raw material.Composition weigh in the ratio that Zn25-25.5wt%, Al3.5-4wt%, Ni0.8-1.0wt%, composite rare-earth modifier 0.6-0.8wt%, surplus are copper after melting in medium frequency induction melting furnace.Melting technology is: first add preheated electrolytic copper, electrolytic nickel, aluminium ingot, after add zinc ingot metal and composite rare-earth modifier, to add in fusion process a small amount of borax cover, add-on is the 0.15wt% of molten metal.After material all melts, be warming up to 1280 DEG C-1300 DEG C, pour into the ingot casting that diameter is φ 80 × 150mm.Anneal is heated to 820 DEG C of insulations furnace cooling after 24 hours, and then the dezincify layer of surperficial 2-3mm is removed in turning, then ingot casting is forged into the bar of 45 × 45mm after 840 DEG C of insulation half an hour.Finally carry out the thermal treatment of two-stage timeliness, namely 820-840 DEG C of insulation is quenched in room temperature machine oil for 1 hour, takes out air cooling to room temperature after being then incubated 0.5 hour in preprepared 100 DEG C of boiling water, then takes out air cooling to room temperature be incubated 0.5 hour in 50 DEG C of water after.Bar after thermal treatment is processed into national standard coupon, room temperature tensile Mechanics Performance Testing is carried out on WE-10 type fluid pressure type tensile testing machine, memorial alloy tensile strength 695.5MPa is recorded, elongation 9.5%, Brinell hardness 186HB after this processing method process.Sample on bar, go out thermal fatigue sample by linear cutter, thermal fatigue specimen size is long 40 mm, wide 10 mm, high 5mm, sample top with v-notch, as shown in Figure 1.Resistance furnace heating is adopted to carry out thermal fatigue test from constraint thermal fatigue tester.Plate tensile sample is installed on four sides of cube jig, ensures that the heating of every block sample is consistent with cool position, and by the upper and lower vertical movement of transmission mechanism, thus the automatization reaching sample heating and cooling completes.Automatic control when employing is established, thermocouple measurement control temperature, sample carries out the thermal cycling of heating Yu cooling between room temperature 20 DEG C to 500 DEG C, adopts counter to carry out Auto-counting, adjust and keeps furnace temperature accurately, water temperature 20 DEG C (flowing tap water).Rapid heating sample, heating, cooling are once as a circulation, and each circulating-heating time is 120s, and entering the water cooling time is 15s, until predetermined cycle index.Often circulate 1000 times, take off sample, surface film oxide is removed in polishing, and surface measurements crack length, sample marking is 1, and thermal fatigue property is shown in Fig. 2.
Claims (4)
1. one kind can be improved the processing method of copper-zinc-aluminum shape memory alloy thermal fatigue property, it is characterized by: with electrolytic copper, No. 0, zinc ingot metal, No. A00, industrial aluminium ingot, 1# electrolytic nickel, composite rare-earth modifier, wherein Nd 10 ~ 15wt%, La 10 ~ 15 wt%, Y 8 ~ 12wt%, Ce 8 ~ 12wt%, Tb 5 ~ 8 wt%, Gd 5 ~ 8 wt%, Pr+Sc+Eu+Ho+Er+Tm+Lu be 10 ~ 20wt%, Zr 3 ~ 6wt%, Ti 2 ~ 5wt%, B 2 ~ 5wt%, Yu Weitong is raw material; Composition weigh in the ratio that Zn25-25.5wt%, Al3.5-4wt%, Ni0.8-1.0wt%, compound rare-earth 0.2-1.0wt%, surplus are copper after melting in medium frequency induction melting furnace; Melting technology is: first add preheated electrolytic copper, electrolytic nickel, aluminium ingot, after add zinc ingot metal and composite rare-earth modifier, to add in fusion process a small amount of borax cover, add-on is the 0.15wt% of molten metal; After material all melts, be warming up to 1280 DEG C-1300 DEG C, pour into the ingot casting that diameter is φ 80 × 150mm; Anneal is heated to 820 DEG C of insulations furnace cooling after 24 hours, and then the dezincify layer of surperficial 2-3mm is removed in turning, then ingot casting is forged into the bar of 45 × 45mm after 840 DEG C of insulation half an hour; Finally carry out the thermal treatment of two-stage timeliness, namely 820-840 DEG C of insulation is quenched in room temperature machine oil for 1 hour, takes out air cooling to room temperature after being then incubated 0.5 hour in preprepared 100 DEG C of boiling water, then takes out air cooling to room temperature be incubated 0.5 hour in 50 DEG C of water after; Bar after thermal treatment is processed into national standard coupon, room temperature tensile Mechanics Performance Testing is carried out on WE-10 type fluid pressure type tensile testing machine, memorial alloy tensile strength 695.5MPa is recorded, elongation 9.5%, Brinell hardness 186HB after this processing method process; Sample on bar, go out thermal fatigue sample by linear cutter, thermal fatigue specimen size is long 40 mm, wide 10 mm, high 5mm, and sample top is with v-notch; Resistance furnace heating is adopted to carry out thermal fatigue test from constraint thermal fatigue tester; Plate tensile sample is installed on four sides of cube jig, ensures that the heating of every block sample is consistent with cool position, and by the upper and lower vertical movement of transmission mechanism, thus the automatization reaching sample heating and cooling completes; Automatic control when employing is established, thermocouple measurement control temperature, sample carries out the thermal cycling of heating Yu cooling between room temperature 20 DEG C to 300 DEG C, 400 DEG C, 500 DEG C, adopts counter to carry out Auto-counting, and adjust and keep furnace temperature accurate, flow tap water water temperature 20 DEG C; Rapid heating sample, heating, cooling are once as a circulation, and each circulating-heating time is 120s, and entering the water cooling time is 15s, until predetermined cycle index, often circulate 1000 times, take off sample, surface film oxide is removed in polishing, surface measurements crack length.
2. a kind of processing method that can improve copper-zinc-aluminum shape memory alloy thermal fatigue property according to claim 1, when composite rare-earth modifier add-on is 0.6-0.8wt%, the copper-zinc-aluminum shape memory alloy of preparation room temperature 20 DEG C to 400 DEG C and following carry out cold cycling time thermal fatigue property excellent.
3. a kind of processing method that can improve copper-zinc-aluminum shape memory alloy thermal fatigue property according to claim 1, anneal be heated to 820 DEG C insulation 24 hours after furnace cooling, then the dezincify layer of surperficial 2-3mm is removed in turning, when again ingot casting being forged into the bar of 45 × 45mm after 840 DEG C of insulation half an hour, the copper-zinc-aluminum shape memory alloy of preparation room temperature 20 DEG C to 400 DEG C and following carry out cold cycling time thermal fatigue property excellent.
4. a kind of processing method that can improve copper-zinc-aluminum shape memory alloy thermal fatigue property according to claim 1, carry out the thermal treatment of two-stage timeliness, namely 820-840 DEG C of insulation is quenched in room temperature machine oil for 1 hour, then air cooling is taken out to room temperature after being incubated 0.5 hour in preprepared 100 DEG C of boiling water, be incubated when taking out air cooling to room temperature after 0.5 hour again in 50 DEG C of water, the copper-zinc-aluminum shape memory alloy of preparation room temperature 20 DEG C to 400 DEG C and following carry out cold cycling time thermal fatigue property excellent.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310230572.4A CN104233130A (en) | 2013-06-12 | 2013-06-12 | Process for improving thermal fatigue property of copper-zinc-aluminum shape memory alloy |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310230572.4A CN104233130A (en) | 2013-06-12 | 2013-06-12 | Process for improving thermal fatigue property of copper-zinc-aluminum shape memory alloy |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN104233130A true CN104233130A (en) | 2014-12-24 |
Family
ID=52222016
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310230572.4A Pending CN104233130A (en) | 2013-06-12 | 2013-06-12 | Process for improving thermal fatigue property of copper-zinc-aluminum shape memory alloy |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104233130A (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102732744A (en) * | 2012-07-18 | 2012-10-17 | 镇江忆诺唯记忆合金有限公司 | Method for improving memory performance of CuZnAl memory alloy |
-
2013
- 2013-06-12 CN CN201310230572.4A patent/CN104233130A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102732744A (en) * | 2012-07-18 | 2012-10-17 | 镇江忆诺唯记忆合金有限公司 | Method for improving memory performance of CuZnAl memory alloy |
Non-Patent Citations (1)
| Title |
|---|
| 许亮等: "不同状态CuZnAl(RE)形状记忆合金热疲劳性能", 《铸造》, vol. 61, no. 12, 31 December 2012 (2012-12-31), pages 1377 - 1382 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102808105B (en) | Method for preparing shape memory copper alloy | |
| CN102312112A (en) | Composite modifier for improving thermal fatigue performances of aluminum-silicon alloy | |
| CN103276240A (en) | Copper-zinc-aluminium-shaped memory alloy for raising thermal fatigue performance | |
| CN105039817B (en) | The preparation method and multicomponent heat-resistant magnesium alloy of a kind of multicomponent heat-resistant magnesium alloy | |
| CN102732744A (en) | Method for improving memory performance of CuZnAl memory alloy | |
| CN103484649A (en) | GH4700 alloy ingot homogenizing treatment method | |
| CN104372203A (en) | Novel alpha titanium alloy and preparation method of panel and bar of alpha titanium alloy | |
| CN103911531A (en) | Al-Mg alloy and preparation method of Al-Mg alloy plate | |
| CN102719705B (en) | Multi-component zinc-aluminium alloy capable of enhancing thermal fatigue property | |
| CN108998635A (en) | The preparation method of anti-oxidant electrothermal alloy | |
| CN103924142A (en) | Magnesium alloy and preparing method thereof | |
| CN104762539A (en) | High-strength and high-abrasion weldable aluminum base alloy | |
| CN104480347A (en) | TiAl-base alloy and heat treatment technique thereof | |
| US20210102280A1 (en) | Zr-based amorphous alloy and manufacturing method thereof | |
| CN105624468A (en) | High-strength and high-tenacity zinc alloy bar/wire and preparation method thereof | |
| CN103131925A (en) | High-strength heat-resisting composite rare earth magnesium alloy | |
| CN102994805A (en) | Extruded zinc alloy and preparation method thereof | |
| CN104630555A (en) | High-strength corrosion resisting brass material and preparation method thereof | |
| CN105369043A (en) | Shape memory alloy with ultrahigh elasticity and high martensite phase transformation critical stress and manufacturing method thereof | |
| CN104233014B (en) | A kind of axial compressor rotor sheet alloy material and preparation method thereof | |
| CN104233130A (en) | Process for improving thermal fatigue property of copper-zinc-aluminum shape memory alloy | |
| CN104342593A (en) | Copper-zinc-aluminum memory alloy for improving phase transformation point stability under hot and cold cycles | |
| CN105695818A (en) | Preparation method of electronic aluminium alloy material | |
| CN104342577A (en) | Copper zinc aluminum memory alloy capable of improving hardness stability under hot and cold cycling | |
| CN104372198A (en) | Method for increasing rolling wearability of copper-zinc-aluminium memory alloy under acidic medium |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20141224 |