Development of Ti-Pd-Ni High Temperature Shape Memory Alloys

Ti-Pd-Ni高温形状记忆合金的研制

• 批准号: 07555185
• 负责人: OTSUKA Kazuhiro
• 金额: $ 6.02万
• 依托单位: University of Tsukuba
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07555185/
• 关键词: shape memory alloy; high temperature shape memory alloy; shape memory characteristics assessment apparatus; Ti-Pd-Ni; Ti-Pd; Ti-Ni; 再結晶; 形状記憶歪; 回復; 逆変態; Ti-Pol; Ti-Pol-Ni

To improve the shape memory characteristics of Ti_<50>Pd_<50-x>Ni_x (0<=x<=50) high temperature shape memory alloys, various experiments were carried out, and the following results were obtained. (1) A new apparatus to assess high temperature shape memory characteristics was developed, utilizing differential transformers to avoid the effect of thermal expansion of various parts of the system. Although some troubles were encountered at the beginning, the troubles were eliminated by using quartz glass rods with very low thermal expansion to detect the strains of specimens. (2) The addition of B to the above alloys were found to be effective to prohibit grain growth, and to the resultant increase of elongation of the alloys. The expected precipitates of TiB_2 were also realized, but the size was too large to be effective. The large grain growth of TiB_2 precipitates were found to originate in the homogenization annealing prosess. Thus, the homogenization treatment was avoided thereafter. … More (3) Since the precipitation hardening of TiB_2 was not effective, another type of precipitation hardening was tried. i.e.the composition of Ti was changed from the stoichiometry of Ti_<50>Pd_<30>Ni_<20>. As a result, the method was found to be effective with introduction of another precipitates. (4) Starting from Ti_<50>Pd_<30>Ni_<20> alloys, 4 types of alloys with B addition, Ti-rich from stoichiometry, and the combination of both, were prepared. Then, as a result of optimization experiment with respect to composition and heat-treatment, the high temperature shape memory characteristics were found to be best for the alloy on Ti-rich side, which were heat-treated at 773K for 1h. (5) Very interesting results were obtained on the recovery・recrystallization of the alloys. i.e. The recovery・recrystallization was found to be controlled by the reverse transformation such that the former follows the latter. (6) Very interesting phenomenon was found such that recrystallization occurs in the martensitic state. However, this means that the recrystallization in the martensitic state becomes one factor determining the upper temperature limit of the alloys. (7) Cyclic experiments are being done using the above new apparatus. However, the cyclic experiments are to be continued in the following year, since the experiments are very time-consuming (i.e.10h/specimen). Less

为了改善Ti_<50>Pd_<50-x>Ni_x （0<=x<=50）高温形状记忆合金的形状记忆特性，进行了各种实验，得到了以下结果：(1)开发了一种新的高温形状记忆特性评估装置，利用差动变压器避免了系统各部分热膨胀的影响。虽然一开始遇到了一些麻烦，但通过使用热膨胀率极低的石英玻璃棒来检测试样的应变，解决了这些麻烦。(2)在上述合金中添加B能有效地阻止晶粒长大，从而提高合金的伸长率。TiB_2的析出物也实现了预期的析出物，但由于析出物的尺寸太大而无法发挥作用。发现TiB_2析出物晶粒的大生长源于均匀化退火过程。因此，此后都避免了均质处理。(3)由于TiB_2的沉淀硬化效果不佳，尝试了另一种沉淀硬化方法。即Ti的组成由Ti_<50>Pd_<30>Ni_<20>的化学计量变化。结果表明，该方法在引入另一种沉淀物时是有效的。(4)从Ti_<50>Pd_<30>Ni_<20>合金开始，制备了4种添加B、化学计量富ti和两者结合的合金。然后，从成分和热处理两方面进行优化实验，发现在773K下热处理1h的富ti侧合金具有最佳的高温形状记忆特性。(5)在合金的恢复再结晶方面获得了非常有趣的结果。即，发现恢复·再结晶是由反向转变控制的，使前者跟随后者。(6)发现了一个非常有趣的现象，即在马氏体状态下发生再结晶。然而，这意味着马氏体状态下的再结晶成为决定合金温度上限的一个因素。(7)正在利用上述新装置进行循环实验。然而，由于实验时间非常长（即10小时/个试样），循环实验将在次年继续进行。少

项目成果

S., Shimizu・et al.: "Improvement of Shape Memory Characteristics by Precipitationhardening of Ti-Pd-Ni Alloys" Materials Lett.34. 23-29 (1998)

S.、Shimizu等人：“通过Ti-Pd-Ni合金的沉淀硬化改善形状记忆特性”Materials Lett.34（1998）。

S.Shimizu, Ya Xu, E.Okunishi, S.Tanaka, K.Otsuka and K.Mitose: "Improvement of Shape Memory Characteristics by Precipitation-hardening of Ti-Pd-Ni Alloys" Materials Lett.Vol.34. 23-29 (1998)

S.Shimizu、Ya Xu、E.Okunishi、S.Tanaka、K.Otsuka 和 K.Mitose：“通过 Ti-Pd-Ni 合金的沉淀硬化改善形状记忆特性”Materials Lett.Vol.34。

Y., Suzuki・et al.: "Effects of Boron Addition on Microstructure and Mechanical Properties of Ti-Pd-Ni High-temperature Shape Memory Alloys" Materials Lett.(in press).

Y.、Suzuki 等人：“添加硼对 Ti-Pd-Ni 高温形状记忆合金的微观结构和机械性能的影响”Materials Lett.（出版中）。

大塚和弘: "Ti-Pd-Ni合金の高温形状記憶特性と回復・再結晶挙動" まてりあ. 37・2. 125-132 (1998)

大冢一宏：“Ti-Pd-Ni 合金的高温形状记忆特性和恢复/再结晶行为”Materia 37・2（1998）。

Ya, Xu・et al.: "High-temperature Shape Memory Characteristics and Recovery・Recrystallization Behavior in Ti-Pd-Ni Alloys" Proc.China-Japan Bilateral Symposium on Shape Memory Alloys(Hangzhou,1997). (in press).

亚、徐等：“Ti-Pd-Ni合金的高温形状记忆特性及恢复·再结晶行为”，中日形状记忆合金双边研讨会论文集（杭州，1997）。