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研究了脉冲电流对2091 Al-Li合金在高速超塑变形时的力学行为及断裂机制的影响。结果表明:施加脉冲电流使2091 Al-Li合金在高应变速度(10~(-2)s~(-1))时仍具有较高的应力应变速度敏感指数和超塑性能。扫描电镜观察表明,施加脉冲电流使2091 Al-Li合金的断裂机制由晶界撕裂转变成典型的超塑断裂-在粒子及晶界处形成孔洞,相互连接以至断裂。
The effect of pulse current on the mechanical behavior and fracture mechanism of 2091 Al-Li alloy during high-speed superplastic deformation was investigated. The results show that 2091 Al-Li alloy has high stress-strain rate sensitivity index and superplasticity at high strain rate (10 ~ (-2) s ~ (-1)) by applying pulse current. Scanning electron microscopy observations show that the pulse current is applied to transform the fracture mechanism of 2091 Al-Li alloy from the grain boundary tearing to the typical superplastic fracture - forming pores in the grain and grain boundaries and connecting them to each other.