The Study of the Mechanism of the All-Round Shape Memory Effect in TiNi Alloy

TiNi合金全方位形状记忆效应机理研究

• 批准号: 60460190
• 负责人: HONMA Toshio
• 金额: $ 3.84万
• 依托单位: TOHOKU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1985
• 资助国家: 日本
• 起止时间: 1985 至 1986
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-60460190/
• 关键词: Thermoelastic Martensitic Transformation; Shape Memory Effect; Precipitation; TiNi Alloy; Aging Treatment; Habit Plane; Shape Memory Alloy; 全方位形状記憶効果

Ni rich TiNi alloys (Ti-51-52at%Ni) exhibit the all-Round Shape Memory Effect by aging under constrain. The aim of this research project is to clarify the mechanism of this All-Round Shape Memory Effect. Shape memory effects of Ti-51 and 52at%Ni specimens were investigasted under the various conditions of constrained aging by means of optical microscope and eleotron microscope. The results are as follows.1. The TTT diagrams of precipitates in this alloy were made between 300-600゜C. Precipitates were <Ti_3> <Ni_4> (precisely <Ti_11> <Ni_14> ), <Ti_2> <Ni_3> and Ti <Ni_3> . Ti <Ni_3> is stable and the others are metastable phases.2. Fine and dispersed precipitates of <Ti_3> <Ni_4> with coherent grain boundary cause the All-Round Shape Memory Effect. This effect does not appear in the case of bigger precipitates grown up.3. The crystal structure of <Ti_3> <Ni_4> is rhombohedral structure (a=6.72 <。!A> , <alpha> =113.9) with ordered atomic arrangement.4. The lenticular precipitate <Ti_3> <Ni_4> has the anisotropy in both of inner (compression stress) side and outer (tension stress) side.5. Against the stress axis, the semimajor axis of presipitate <Ti_3> <Ni_4> is perpendecular in the compression side and parallel in the tension side, respectively.6. The growth direction of intermediate (R) phase and martensite (M) phase which generate in specimen during cooling is the best convenient direction which accomodates the internal strain between parent phase and precipitates, especially the strain in the direction of semiminor axis of precipitate. Therefore, after the growth of R phase with single variant around precipitate, martensite phase appears. As the result ofthe difference of lattice constant the compression stress side elongates and the tension stress side shrinks in bending constrained specimen during cooling. It is concluded that the shape of the specimen changes spontaneously and the All-Round Shape Memory Effect appears during cooling.

富Ni的TiNi合金（ti -51 ~ 52at%Ni）在约束时效下表现出全方位的形状记忆效应。本研究的目的是阐明这种全方位形状记忆效应的机制。利用光学显微镜和电子显微镜研究了不同约束时效条件下Ti-51和52at%Ni试样的形状记忆效应。结果如下：1。该合金中析出物的TTT图在300-600℃之间制作。析出相为<Ti_3> <Ni_4>（确切地说<Ti_11> <Ni_14>）， <Ti_2> <Ni_3>和Ti <Ni_3>。Ti <Ni_3>为稳定相，其余为亚稳相。<Ti_3> <Ni_4>细小分散的晶界一致的析出相产生了全方位的形状记忆效应。这种影响不出现在较大的沉淀长大的情况下。<Ti_3> <Ni_4>的晶体结构为菱形体结构（a=6.72 < . !）A>, < α > =113.9)的有序原子排列。透镜状析出物<Ti_3> <Ni_4>在内（压应力）侧和外（拉应力）侧均具有各向异性。相对于应力轴，presiate <Ti_3> <Ni_4>的半长轴在压缩侧垂直，在拉伸侧平行。试样在冷却过程中产生的中间(R)相和马氏体(M)相的生长方向是最方便容纳母相与析出相之间内部应变的方向，尤其是析出相半轴方向的应变。因此，R相长大后，在析出相周围出现单一变异的马氏体相。由于晶格常数的差异，弯曲约束试样在冷却过程中压缩应力侧拉长，拉应力侧收缩。结果表明，在冷却过程中，试样的形状发生了自发的变化，并出现了全方位的形状记忆效应。

项目成果

Minoru Nishida; C.M.Wayman; Toshio Honma: "Phase Transformation in a <Ti_50> <Ni_47.5> <Fe_2.5> Shape Memory Alloy" Metallography. 19. 99-113 (1986)

西田稔；

Toshio Honma: "The Effect of Aging on the spontaneous Shape Change and the All-Round Shape Memory Effect in Ni-Rich TiNi Alloy" Proc.Intern.Conf. on Martensitic Transformation (ICOMAT-86). 709-716 (1986)

Toshio Honma：“时效对富镍 TiNi 合金自发形状变化和全方位形状记忆效应的影响”Proc.Intern.Conf。

西田稔,C.M.Wayman,本間敏夫: Metallurgical Trasaction(A). 17A. 1505-1515 (1986)

Minoru Nishida，C.M.Wayman，Toshio Honma：冶金交易（A）1505-1515（1986）。

Minoru Nishida; C,M,Wayman; Toshio Honma: "Precitation Process in NearEquiatomic TiNi Shape Memory Alloys" Metallurgical Transaction (A). 17A. 1505-1515 (1986)

西田稔；

西田稔,C.M.Wayman,貝沼亮介,本間敏夫: Scripta Met.20. 899-904 (1986)

Minoru Nishida、C.M.Wayman、Ryosuke Kainuma、Toshio Honma：Scripta Met.20 (1986)。