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采用Gleeble 1500D热模拟试验机对ZK60-1.0Er镁合金的热压缩变形行为进行了研究。热压缩参数应变速率?为0.0001,0.001,0.01和1.0 s~(-1);变形温度T为160,260,320和420℃。结果表明:ZK60-1.0Er镁合金的热压缩变形过程主要为动态回复DR和动态再结晶DRX。通过Zener-Hollomon参数建立了ZK60-1.0Er镁合金热压缩本构方程,根据本构方程计算的理论应力值与实际应力值吻合;同时还根据材料动态模型建立了该种合金的热加工图,并且通过对微观组织的观察和分析可知:该种镁合金的热加工图包含低温高应变速率和高温低应变速率2个失稳区域。该种镁合金适宜的热加工区间为:225~420℃,0.01~1.0 s~(-1),在该区域内存在1个功率耗散效率的峰值,η_(max)=45%。稀土相的存在促进了ZK60-1.0Er镁合金的动态再结晶形核,平均变形激活能Q=152.5 k J/mol,该合金的微观变形机制为晶界滑移和晶格自扩散导致的动态回复和动态再结晶。
The hot compressive deformation behavior of ZK60-1.0Er magnesium alloy was studied by Gleeble 1500D thermal simulation test machine. The thermal compression parameters of strain rate? Are 0.0001, 0.001, 0.01 and 1.0 s -1; and the deformation temperature T is 160, 260, 320 and 420 ° C. The results show that the hot compression deformation process of ZK60-1.0Er magnesium alloy is mainly dynamic response DR and dynamic recrystallization DRX. The thermo-compression constitutive equation of ZK60-1.0Er magnesium alloy was established by Zener-Hollomon parameters. The theoretical stress calculated by the constitutive equation is consistent with the actual stress value. At the same time, the hot working diagram of the alloy was established according to the dynamic model of the material. And through the microstructure observation and analysis shows that: the magnesium alloy hot working diagram contains low temperature and high strain rate high temperature and low strain rate two instability zone. The suitable thermal processing range of this kind of magnesium alloy is 225 ~ 420 ℃, 0.01 ~ 1.0 s ~ (-1). There is one peak of power dissipation efficiency in this region, η max = 45%. The existence of rare earth phase promotes the dynamic recrystallization nucleation of ZK60-1.0Er magnesium alloy with the average deformation activation energy Q = 152.5 kJ / mol. The microscopic deformation mechanism of the alloy is the result of grain boundary slip and lattice self-diffusion Reply and dynamic recrystallization.