经电脉冲处理的轧制AZ31镁合金组织与性能演变

Microstructure snd Mechanical Properties of Rolled AZ31 Alloy Sheets Processed by Electropulsing Treatment

利用超景深显微镜、扫描电镜(SEM)、电子背散射衍射(EBSD)研究了高能量脉冲电流对10%、15%、20%不同轧制变形量AZ31镁合金组织演化与力学性能的影响。当变形量为20%的轧制板材经电流密度为4.16×10~9 A/m^2、脉宽为30μs、频率为100 Hz的脉冲电流处理10 min后,平均晶粒尺寸由150μm细化至20μm,抗拉强度提升至265 MPa,伸长率可达19.7%。同时,分析了此实验参数下电脉冲处理过程中热效应与非热效应对再结晶的影响,发现热效应在再结晶过程中占主导作用,并揭示了非热效应的作用机理。

The microstructure evolution of rolled AZ31 alloy sheets with 10%,15% and 20% rolling reduction by electropulsing treatment（EPT） was investigated by VHX-2000 optical microscope and scanning electron microscope equipped with electron backscattered diffraction（EBSD）. After EPT with 30 μs in pulse-width,4.16×10~9 A/m^2 in current density and 0.003 in duty ratio for 10 min processing time,the average grain size of AZ31 alloy is refined from 150 μm to 20 μm,the tensile strength is improved to 265 MPa and the elongation can reach 19.7%. The effect of the thermal and athermal effect on the recrystallization during EPT was analyzed. The result shows that the athermal effect plays a major role in recrystallization and the mechanism of the athermal effect was also revealed.