应变水平对锆合金动载下塑性变形机制的影响

Influences of Strain on the Plastic Deformation Mechanism of Zirconium Alloy subjected to dynamic loading

摘要:

本文基于试验设计研究了应变参数对锆合金动载下塑性变形机制的影响。通过控制应变速率，采用应变限位环的方法实现了锆合金高应变速率下应变参数的单一分离，应变速率为2300 s-1时，获得了四个不同的应变水平：0.11、0.21、0.30、0.33。结果表明：形变带和转变带是锆合金不同应变阶段塑性变形的重要方式，形变带内部以严重变形的晶粒组成，而转变带内部主要由100～300 nm的细小等轴晶粒组成。基于锆合金高应变速率不同应变下微观组织表征，预测了应变参数对锆合金动载下塑性过程的影响。

Abstract:

The influence of strain on the plastic deformation mechanism of zirconium alloy subjected to dynamic loadings was investigated by means of the experimental design in this paper. The strain parameter of zirconium alloy subjected to dynamic loading was only separated by the strain stopping rings and the the controled strain rate, and four strain levels including 0.11, 0.21, 0.30 and 0.33 were obtained at a strain rate of 2300 s_-1. The results show that the deformed bands and transformed bands were considered as the dominant plastic deformaton mechanism of zirconium alloy under different strain stages. The deformed bands were mainly composed of the severe deformed grains, and the transformed bands mainly composed of the ultrafine and equiaxed grains with the mean diameter of about 100~300 nm were confirmed. Based on microstructural characterization of zirconium alloy under high strain rate and different strains, the plastic deformation process of zirconium alloy subjected to different strain parameters was speculated.