Fe基α相合金的冲击相变及其对层裂行为的影响研究

Phase transition and influence of phase transition on spall in α phase Fe-based alloy

利用正向加载和逆向加载相结合的实验方法,实验研究了从低压到高压三种不同压力范围内Fe基α相合金(Fe-85.03wt%,Mn-7.63wt%,Ni-7.01wt%,Al-0.3wt%)的冲击相变和卸载逆相变历程及对应加载状态的层裂行为特征.给出了Fe基α相合金含冲击相变和卸载逆相变的加卸载Hugoniot线,发现冲击相变阈值、逆相变阈值和冲击加载压力共同决定其冲击加卸载历程,冲击相变强烈影响其层裂行为,导致样品发生了"异常"层裂.利用获得的冲击加卸载历程从应力波相互作用的角度解释了"异常"层裂的成因,探讨了冲击相变对层裂行为的影响机制.

This paper provides an investigation of the phase transition and the spalling characteristics induced during shock loading and unloading in an α phase Fe-based alloy.Two kinds of impact set-ups are used.One is referred to as the direct impact,and the other is the reverse impact.The shock Hugoniot and the release stress-volume adiabat of the α phase Febased alloy are obtained.And the results show that the history of loading and unloading is determined by the relationship among the phase transition threshold and the reverse transition threshold and the shock pressure.It is found that abnormal spallations happen in the α phase Fe-based alloy sample as the pressure exceeds the phase transition threshold.Such abnormal spalling phenomena are believed to be related to the shocked α→ε phase transition,and a possible reason for the abnormal spalling is discussed also from the interaction process of stress wave.