FeMnNi合金高压加卸载历程测量和相变层裂分析

 采用VISAR和X光联合测试技术，利用等厚对称和逆向碰撞法测量了FeMnNi合金高压加卸载历程和相变层裂信息。加载过程中，FeMnNi合金样品发生α→ε相转变，相变波速大于塑性波速，在撞击面上相变波与塑性波合并成单一相变波；卸载过程中，FeMnNi合金样品可能发生了逆相变，形成了除合并相变波在自由面反射中心稀疏波R以外的两道卸载波S1和S2。等厚对称高压加载下，FeMnNi合金样品发生了二次层裂。分析中心稀疏波R、卸载波S1和S2在样品中的传播作用过程，发现样品发生冲击相变和卸载逆转变是导致其等厚对称高压加载下发生二次层裂行为的主要原因。

Loading and Unloading Process,Phase Transition,and Spallation in FeMnNi Alloy under High Shock-Compression

Using VISAR interferometer and X-ray, phase transition and spalling behavior of FeMnNi alloy under high pressure were studied by symmetric impact and reverse impact experiments. In the loading process, the FeMnNi alloy experienced a α→ε phase transformation, the velocity of the transition was greater than that of the plastic wave, and thus incorporated into a single phase transition wave. In the unloading history, the reverse phase transition also might take place and the rarefaction waves S1 and S2 formed besides the center-rarefaction wave R. The multi-spallation happened for symmetrical and same thickness high pressure in FeMnNi alloy. By analyzing the interaction among the rarefaction waves S1, S2 and the rarefaction R, it was found that the phase transition and reverse transition of the sample are the main causes of multi-spallation.