电脉冲对轧制AZ31镁合金组织与性能的影响

Effect of electropulsing treatment on the microstructure and the properties of the rolled AZ31 alloy

摘要:

本文研究了电脉冲处理对轧制变形AZ31镁合金组织演化与力学性能的影响。使用脉冲电源产生的高电流密度低占空比电脉冲促进了变形AZ31镁合金内部的再结晶进程。通过对不同参数脉冲处理的对比分析，研究了电脉冲的热效应与非热效应的作用，揭示了电脉冲促进再结晶的作用机理。结果表明：AZ31镁合金经过脉宽为20μs、电流密度3.508×109 A/m2、占空比为0.002的电脉冲处理5.5 min后，在电脉冲的非热作用下发生再结晶，平均晶粒尺寸由72μm降低至2μm，抗拉强度提升85%，达到295 MPa，延伸率达到20%。

Abstract:

In this paper, the effect of electroplsing treatment (EPT) on the microstructure evolution and the mechanical properties was studied. The recrystallization of the deformed AZ31 magnesium alloy was accelerated by using EPT with high current density and low duty ratio. EPT with different parameters was analized. The thermal and athermal effect of EPT is researched and the mechanism of the recrystallization under EPT was also revealed. The results indicated that the deformed AZ31 magnesium alloy recrystallized under the EPT for 5.5 minutes. After EPT with a pluse-width of 20 μs, a current density of 3.508×109 A/m2, a duty ratio of 0.002 and a processing time of 5min, the average grain size of AZ31 alloy is refined from 72 μm to 2 μm, the tensile strength is 295 MPa, and the elongation is 20%.