镁合金复合变形过程中的动态再结晶及微观组织演变规律研究

Study on Dynamic Recrystallization and Microstructure Evolution of Magnesium Alloy in Process of Composite Deformation

对挤压态AZ31镁合金进行了压痕-压平复合变形工艺实验研究,分析了复合变形工艺参数对镁合金动态再结晶组织及孪晶组织的影响规律。研究结果表明,经过复合变形后,AZ31镁合金的微观组织呈现孪晶组织和动态再结晶组织。复合变形系数和变形温度对镁合金微观组织影响明显。随着复合变形系数的增大和变形温度的提高,动态再结晶体积分数随之增大,动态再结晶组织逐渐增多,最后覆盖原始孪晶组织,得到分布均匀且细小的等轴晶,有效改善了镁合金材料的组织性能。

Indentation-flattening compound deformation technology(IFCDT) of extruded AZ31 magnesium alloy was studied experimentally, and the effect law of deformation parameters on the dynamic recrystallization structure and twin structure of magnesium alloy was analyzed. The results show that the microstructure of AZ31 magnesium alloy presents twin structure and dynamic recrystallization structure after compound deformation. The effect of the compound deformation coefficient and deformation temperature on the microstructure of magnesium alloy is obviously. With the increase of the compound deformation coefficient and deformation temperature, the volume fraction of dynamic recrystallization increases,and the dynamic recrystallization structure increases gradually. Finally, the original twin structure is covered. Refined and equiaxed grains with uniform distribution are obtained, which effectively improves the microstructure and properties of the magnesium alloy.