环境介质对形状记忆合金弹簧记忆回复效应的影响*

针对SAM电火花加工机器人加工时常用的3种工作介质水、煤油和乳化液，研究了SMA弹簧的记忆恢复变形特性和变形规律。结果表明，对应不同的环境介质，SMA弹簧的记忆回复变形量与驱动电流间存在一一对应关系，通过控制驱动电流可控制记忆回复变形量。在不同环境介质中SMA弹簧的记忆回复变形速度的变化趋势是一致的，都是先随着回复位移的增加而增加，在接近中间段时达到最大，然后随着位移的增加而减小。驱动电流是对SMA弹簧动态变形速度影响最 明显的参数，通过选择合适的驱动电流可有效地控制SMA弹簧的回复变形速度。

Influence of environment medium on memory restoring effect of shape memory alloy spring

In the light of three kinds of work medium, such as water, kerosene and emulsion commonly used by SMA electrical discharge machining robot, memory restoring deformation characteristics and deformation law of SMA spring are studied. Experimental results show that one-one relationships exist between memory restoring deformation of SMA spring and drive current. Memory restoring deformation of SMA spring can be controlled through controlling drive current. The variety trends of memory restoring speed of SMA spring for different environment mediums are identical. In any environment mediums, the deformation velocity of SMA spring increases with increasing of restoring displacement, and reaches maximum value at the intermediate position. Then the velocity gradually decreases with increasing of restoring displacement. The drive current is the most important parameter that affects the restoring velocity of SMA spring, so its deformation velocity can be effectively controlled by selecting suitable drive current.