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本文利用透射式电子显微镜研究了35CrMnSi、4Cr5MoVSi钢和粉末冶金高强度低塑性钨合金W-7Ni-3Fe制成的模拟弹侵彻穿甲后的显微组织。提出某些静态脆性材料在高速冲击下显现出明显的增塑效应。并认为高速冲击下材料的塑变机制不同于静态的位错滑移机制,关于材料的动态塑性流变机制,还有待进一步深入细致的研究。本文还将金属高速冲击下的塑变形态分为热塑性失稳(绝热剪切)和均匀塑性流变二种,利用穿甲试验证明前者是有害的变形,而后者是有利的。此外,本文还试图根据塑性流变机制的改变提出村料动态与静态性能研究的“分界应变率”(10~3秒~(-1)～10~4秒~(-1))供讨论或参考。
In this paper, the microstructures of 35CrMnSi, 4Cr5MoVSi steel and powder metallurgy high strength and low plasticity tungsten alloy W-7Ni-3Fe were studied by transmission electron microscopy. It is suggested that some static brittle materials show obvious plasticizing effect under high-speed impact. It is considered that the mechanism of plastic deformation under high-speed impact is different from the static dislocation slip mechanism. The dynamic plastic rheological mechanism of the material needs to be further studied in detail. In this paper, the plastic deformation modes under high-speed impact of metal are also divided into two types: thermoplastic instability (adiabatic shear) and uniform plastic rheology. The use of armor-piercing tests proves that the former is detrimental and the latter is advantageous. In addition, according to the change of plastic rheological mechanism, this paper also attempts to propose “demarcation strain rate” (10 ~ 3s -1 ~ 10s ~ 4s -1) for the study of dynamic and static properties of the village material for discussion or reference.