冲击下c轴硫化镉单晶的相变特性

Phase Transition Behavior of c-Axis Cadmium Sulfide Single Crystal Under Shock Loading

采用前后压电石英计方法系统地研究了c 轴硫化镉单晶在高速平面撞击下的相变特性,首次得到了这种材料的冲击Hugoniot 曲线,并观察到与相变机制有关的应力松弛和双波结构现象.与弹塑性波不同的是,这种由于相变引起的双波结构波形的弹性前驱波,在一定压力范围内,其幅值不随传播距离而衰减.实验结果推断出,相变点同时可能又是屈服点,相变与塑性两种机制也许存在某种耦合作用。

The phase transition behavior of c-CdS single crystal under high veloc- ity planar impact is systematically investigated by means of the front and rear quartz gauge technique.The Hugoniot curve of this material with phase transition is obtained for the first time.The stress relaxation and two-wave structure,which are related to phase transition,are observed.Below a thresh- old of stress the elastic precusors induced by phase transition do not decay apparently with travelling distance.This is quite different from the elastic- prastie waves.Besides,the experimental results show that the initial point of phase transition is also a yield point for this material,and consequently there may exist some certain coupling interaction between the mechanisms of phase transition and yielding.