冲击相变对FeMnNi合金层裂行为影响研究

INFLUENCE OF PHASE TRANSITION ON SPALLING BEHAVIOR IN FEMNNI ALLOY

通过逆向加载和等厚对称碰撞实验相结合的方法,确定了FeMnNi合金含冲击相变和卸载逆相变的完整加卸载物理过程和对应加载状态的层裂特征.采用修正的Boettger模型与非平衡两相相变理论模型,成功模拟再现了实验过程,解释了冲击相变、卸载逆相变及卸载冲击波形成的物理机理.利用获得的冲击加卸载历程,从应力波相互作用的角度分析了等厚对称碰撞样品形成"异常"层裂的物理原因,指出层裂发生的机制正是由于受载样品发生了冲击相变和卸载逆相变.

This paper provides an investigation of the phase transition and spalling characteristics induced by shock loading and unloading process in FeMnNi alloy through two symmetric impact experiments of same thickness and reverse impact technique.The experimental process is simulated successfully from the non-equilibrium two-phase model and the modified Boettger＇s model.The physical mechanisms of the shock phase transition and reverse transition as well as rarefaction shock wave formation are studied.A possible reason for the abnormal spalling phenomenon in the experiments is also discussed from the view of the interaction process of stress wave.It is found that the phase transition and reverse transition induced the spallation in the FeMnNi alloy samples.