限制模压变形1060纯铝的组织演化与晶粒细化

Microstructural evolution and grain refinement of 1060 pure Al processed by constrained groove pressing

设计平行模压变形、180°交叉模压变形、90°交叉模压变形对1060纯铝进行系列限制模压变形(CGP)试验,采用透射电镜研究该材料在不同变形工艺下的组织演化规律和晶粒细化速率。结果表明:变形工艺不影响组织的演化规律,但显著影响晶粒细化速率、晶粒细化效果以及大角度晶界的形成;90°交叉模压变形最优。在相同的变形温度、变形速率和应变累积条件下,所能达到的晶粒细化速率和大角度晶界的数量取决于剪切变形模式。

In order to well understand the role of the accumulative strain and the effects of shear strain plane in the grain refinement during constrained groove pressing （CGP）, the microstructural evolution and the grain refinement rate of 1060 aluminum alloy processed by CGP, such as parallel CGP, 180° cross CGP and 90° cross CGP, were investigated by transmission electron microscopy. The results show that the microstructural evolution is independent of the pressing conditions. But the processing conditions significantly affect the grain refinement rate, final grain size and boundaries misorientation, and the 90° cross CGP is the most effective. It is reasonable to conclude that, in the same pressing temperature, strain rate and accumulative strain, the grain refinement rate, final grain size and boundaries misorientation are determined by the shear strain plane.