Ni-Ti形状记忆合金侵彻变形与断裂研究

Deformation and Fracture of Ni-Ti Shape Memory Alloys under the Penetration of Projectiles

研究了Ni-Ti形状记忆合金在高速冲击条件下的侵彻过程。利用光学显微镜对Ni-Ti形状记忆合金在高速冲击后的微观组织进行考察,分析Ni-Ti合金板材的损伤和断裂。结果表明:奥氏体相为基的Ni-Ti形状记忆合金板材,在高速冲击过程中,发生应力诱发马氏体相变;板材内形成剪切带、微裂纹等形式的损伤,导致材料发生变形和破坏;裂纹按着微孔洞聚集型机制扩展。

Damage and fracture of Ni-Ti plate during high velocity impact was investigated. The deformation microstructures were studied by optical microscope. The results indicate that stress induced martensitic（SIM） phase transformation occurs in Ni-Ti plate matrix for Austenite phase in the process of penetration. Deformation and fracture of Ni-Ti plate appear due to shearing band and micro-crack nucleated in interface. Fracture mechanisms are micropore nucleation, growth and coalescence.