Development of Two-way Properties of Shape Memory Alloy and its Applications to Micro-device

在本研究项目的第一年(2003)，我们进行了系统的实验，以研究TiNi(具有重要工业意义)形状记忆合金在一般热机械加载条件下的基本热力学性能。即，对TiNi形状记忆合金薄壁试件施加轴向力和扭矩的联合载荷，研究了TiNi形状记忆合金在复杂载荷条件下的复杂行为。在第一年的研究中，为新的工业应用扫清了可能性，特别是对于运动复杂的微驱动器。在本研究工作的最后一年，我们在过去一年中取得了许多基础性和系统性的实验结果的基础上，系统地研究了具有驱动器功能的TiNi合金的双向形状记忆效应。双向属性可以通过所谓的训练产生，各种训练方案产生各种有趣的双向属性。此外，有效的训练也产生了更高水平的TiNi合金的双向效应。在此，我们尝试了几种训练方案，采用复合加载和多次温度变化的方法对TiNi合金进行了实验，并测量了页岩双向记忆应变以及产生的应力。根据这些实验结果，利用TiNi形状记忆合金设计了一种新型的具有复杂行为(三维行为)的微致动器。

In the first year of this research project (2003), we performed the systematic experiments in order to investigate the fundamental thermo-mechanical properties of TiNi (practically of industrially important) shape memory alloy under the general thermo-mechanical loading conditions. That is, we applied the combined load of axial force and torque to the thin-walled tubular specimen of TiNi shape memory alloy and investigate the complicated behaviors of TiNi shape memory alloy under complex loading conditions. In this first year research, the possibility of new industrial applications was cleared, especially for the micro-actuator with complicate movements.In the final year of this research work, on the basis of many fundamental and systematic experimental results obtained in the last year, we investigated two-way shape memory effect of TiNi alloy which produces the actuator function, systematically. The two-way properties can be produced by the so-called training, and various training programs produce the various interesting two-way properties. Also, the effective training produces the higher level two-way effect of TiNi alloy. Here, we tried several training program experimentally to TiNi alloy by using the complex loading and several temperature changes, and measured the two-way shale memory strain as well as the produced stress. According to these experimental results, new micro-actuator which can behave in complex way (three dimensional manner) is found to be designed by TiNi shape memory alloy.