利用铸造法制备了Mg-8.08Gd-2.41Sm-0.3Zr合金,对该合金进行均匀化处理,然后进行热压缩实验,研究了Mg-8.08Gd-2.41Sm-0.3Zr合金在变形温度为350～500℃、应变速率为0.002 s-1、0.01 s-1、0.1 S-1和1 S-1及最大变形量为50％条件下的变形行为,计算了该合金的热变形激活能,构建了合金高温塑性变形的本构关系,建立了合金的热加工图.结果表明:Mg-8.08Gd-2.41Sm-0.3Zr合金的流变应力随着变形温度的升高或者应变速率的降低而显著降低,合金发生动态回复与再结晶,其热变形激活能为Q=213.693 kJ/mol;合金高温变形时存在两个失稳区:T=430～500℃、(ε)=0.37～1 s-1以及T=350～390℃、(ε)=0.006～1 s-1;合金的能量耗散率大于30％的区域有T=370～430℃、(ε)=0.37～1 s-1,T=390～500℃、(ε)=0.006～o.37 s 1以及T=350～500℃、(ε) =0.002～0.006 s-1,这些区域适合进行热加工.%Mg-8.08Gd-2.41Sm-0.3Zr alloy was prepared by melting and casting method.The hot compression tests were performed on Mg-8.08Gd-2.41Sm-0.3Zr alloy after homogenizing treatment.Hot deformation behavior was investigated at the temperature ranging from 350 ℃ to 500 ℃,strain rate ranging from 0.002 s-1 to 1 s-1 and the maximum deformation of 50％.Deformation activation energy was calculated,the constitutive equation of the plastic deformation of Mg-8.08Gd-2.41Sm-0.3Zr alloy was obtained and the hot processing map was drawn.The results showed that the flow stress decrease with the increase of temperature or the decrease of the strain rate.The dynamic recover and dynamic recrystallization occur obviously during hot compression of Mg-8.08Gd-2.41Sm-0.3Zr alloy.The deformation activation energy was found to be about 213.693 kJ/mol.Two instability zones of flow behavior are established as follows:T=430-500 ℃,(ε) =0.37-1 s 1 and T=350-390 ℃,(ε)=0.006-1 s-1.The efficiency of power dissipation was above 30％ when deformed at T=370-430 ℃,(ε) =0.37-1 s 1;T=390-500 ℃,(ε)=0.006-0.37 s-1 and T=350-500 ℃,(ε) =0.002-0.006 s-1.The three areas were the optional processing parameters of hot deformation.
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