ABSTRACT

The hot compression features and microstructural evolution of Mg–Pb–Al–1B–0.4Sc alloy deformed at the strain rate range of 0.001–1 s⁻¹ and the temperature range of 493–613 K were investigated by isothermal compression tests. The results show that the flow stress is significantly influenced by deformation conditions. The true stress decreases with the raised temperature or the reduced strain rate. The Zuzin-type model and Arrhenius-type constitutive model were employed to predict the flow behaviour of Mg–Pb–Al–1B–0.4Sc alloy. The values of $MARE$ and $RMSE$ in the Arrhenius-type model are 6.353% and 9.595, respectively, which are smaller than the 13.653% and 24.662 of the Zuzin-type model, indicating that the Arrhenius-type model is more suitable for predicting the flow stress of this alloy. The processing maps and microstructure show that the optimum strain rates and temperatures are 0.001–0.015 s⁻¹ and 550–613 K, respectively.

摘要

通过等温压缩试验研究了Mg-Pb-Al-1B-0.4Sc 合金在 0.001-1 s ^-1应变速率范围和 493-613 K 温度范围内变形的热压缩特征和显微组织演变。结果表明，流变应力受变形条件的影响显着。真实应力随着温度升高或应变速率降低而降低。Zuzin型模型和Arrhenius型本构模型被用来预测Mg-Pb-Al-1B-0.4Sc合金的流动行为。的价值$米\mathrm{一种}\mathrm{电阻}乙$ 和 $\mathrm{电阻}米秒乙$在Arrhenius型模型中分别为6.353%和9.595，小于Zuzin型模型的13.653%和24.662，说明Arrhenius型模型更适合预测该合金的流变应力。加工图和微观结构表明，最佳应变速率和温度分别为 0.001-0.015 s ^-1和 550-613 K。