Effects of deformation parameters on microstructure and texture of Mg−Zn−Ce alloy

变形参数对Mg−Zn−Ce合金显微组织和织构的影响

Compression tests were performed on the Mg−6Zn−0.5Ce(wt.%)alloy using a Gleeble−1500 thermomechanical simulator testing system at temperatures of 250,300,350℃ and strain rates of 0.001,0.01,0.1 s^−1.The microstructure and texture evolution of the Mg−6Zn−0.5Ce alloy during hot compression were investigated by optical microscopy(OM)and electron backscattered diffraction(EBSD).The results showed that Zener−Hollomon parameters obtained from the deformation processes had a significant effect on the dynamic recrystallization and texture of the Mg−6Zn−0.5Ce alloy.The fraction of undynamically recrystallized(unDRXed)regions increased,and the dynamically recrystallized(DRXed)grain size decreased with increasing the Zener−Hollomon parameters.The texture intensity of the DRXed regions was weaker compared with that in the unDRXed regions,which resulted in a sharper texture intensity in the samples deformed with higher Zener−Hollomon parameters.The increase in recrystallized texture intensity was related to preferred grain growth.

采用Gleeble−1500热模拟试验机在不同温度(250,300,350℃)和应变速率(0.001,0.01,0.1 s^−1)下对Mg−6Zn−0.5Ce(质量分数,%)合金进行热压缩试验,采用光学显微镜和电子背散射衍射技术研究热压缩变形过程中合金的显微组织和织构演变。结果表明,由变形工艺决定的Zener−Hollomon参数对Mg−6Zn−0.5Ce合金的动态再结晶和织构具有重要影响。随着Zener−Hollomon参数的增大,未再结晶区的体积分数增大且动态再结晶晶粒尺寸减小。再结晶区的织构强度弱于未再结晶区的织构强度,这使经较高Zener−Hollomon参数变形的试样呈较高的织构强度。再结晶织构强度的增加与晶粒择优生长有关。