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研究了ZK31-1.5Y镁合金在变形温度为250~450℃、应变速率为0.001~1 s-1条件下的热压缩变形特性,基于动态材料模型建立了热加工图,并结合真应力-真应变曲线确定了该合金在实验条件下的热变形机制及最佳工艺参数。结果表明:ZK31-1.5Y合金的真应力-真应变曲线主要以动态再结晶和动态回复软化机制为特征,峰值应力和稳态应力随变形温度的降低或应变速率的升高显著增加。合金功率耗散图和失稳图中分别包含了3个效率峰值区和1个马鞍形流变失稳区,峰区效率范围为38%~65%,叠加后形成的加工图给出了实验参数范围内热变形时的最优工艺参数,其热变形温度为350~450℃、应变速率为0.1~1 s-1。当应变量由0.1~0.6逐渐增大时对加工图分布规律影响不大。
The hot compression deformation characteristics of ZK31-1.5Y magnesium alloy at deformation temperature of 250-450 ℃ and strain rate of 0.001-1 s-1 were studied. The hot working drawing was established based on the dynamic material model. Combined with the true stress-true The strain curve determined the thermal deformation mechanism and the optimum process parameters of the alloy under the experimental conditions. The results show that the true stress-true strain curve of ZK31-1.5Y alloy is mainly characterized by dynamic recrystallization and dynamic recovery softening mechanism. The peak stress and steady stress increase with the decrease of deformation temperature or the increase of strain rate. The alloy power dissipation diagram and the instability diagram respectively include three efficiency peak regions and one saddle-shaped rheological instability region, and the efficiency range of the peak region is 38% -65%. The processing diagram formed after the superposition shows experiments The optimum parameters for thermal deformation in the range of parameters are the thermal deformation temperature of 350 ~ 450 ℃ and the strain rate of 0.1 ~ 1 s-1. When the amount of strain increases gradually from 0.1 to 0.6, it has little effect on the distribution of machining patterns.