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

在该研究项目的第一年（2003年），我们进行了系统的实验，以研究TiNi（实际上是工业上重要的）形状记忆合金在一般热机械载荷条件下的基本热机械性能。即对TiNi形状记忆合金薄壁管状试样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，明确了新的工业应用的可能性，特别是对于具有复杂运动的微致动器。在本研究工作的最后一年，我们在去年获得的许多基础和系统的实验结果的基础上，系统地研究了产生作动器功能的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。同时，有效的训练可以产生更高水平的TiNi合金双向效应。在此基础上，通过复杂加载和多次温度变化对TiNi合金进行了多种训练方案的实验，并测量了双向页岩记忆应变和产生应力。根据这些实验结果，利用TiNi形状记忆合金设计了能够以复杂方式（三维方式）工作的新型微致动器。

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.