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对Mg-Gd-Y合金分别使用准静态压缩试验机、分离式霍普金森压杆、平头弹丸侵彻加载,研究了该合金在1×10-3,1×103,1×104s-1时,应变率对其断裂机制的影响。研究结果表明,在应变率为1×10-3s-1时,呈现出脆性解理断裂特征;当应变率增加为1×103s-1时,动态压缩后断口除了解理片层外,还出现了热软化带,变形局域化是裂纹形核的通道,最终导致材料的失效。在应变率约为1×104s-1时,稳定侵彻阶段,绝热剪切带是更高应变率下导致材料断裂的原因,特定位置的绝热剪切带为相变带,应变率的提高有利于形成相变带。应变率是通过影响Mg-Gd-Y合金的热软化效果而影响其断裂机制的。
The Mg-Gd-Y alloys were respectively quasi-static compression testing machine, split Hopkinson pressure bar, flat-head projectile penetration loading, the alloy at 1 × 10-3,1 × 103,1 × 104s-1 , Strain rate on the fracture mechanism. The results show that when the strain rate is 1 × 10-3s-1, brittle cleavage fracture characteristics appear; when the strain rate increases to 1 × 103s-1, in addition to the dynamic compression fracture in addition to cleavage sheet, there The thermal softening zone, the deformation of the localization of crack-shaped nucleation channel, eventually leading to the failure of the material. At a strain rate of about 1 × 10 4 s -1, the adiabatic shear zone is the cause of fracture at higher strain rates due to stable penetration. The adiabatic shear zone at a particular location is a phase transition zone with an increase in strain rate Conducive to the formation of phase transition zone. Strain rate affects the fracture mechanism by affecting the thermal softening effect of Mg-Gd-Y alloy.