AZ31镁合金无缝管挤压动态再结晶数值模拟研究

通过热压缩实验得出温度在300~450℃,应变率为0.01~1 s-1时的应力-应变曲线,建立了AZ31镁合金的动态再结晶模型。该模型用于AZ31镁合金无缝管挤压过程中动态再结晶过程的数值模拟,并通过金相观察得以实验验证。结果表明,在挤压速度确定的情况下,挤压温度对动态再结晶分数的影响最为明显。随着挤压温度的升高,动态再结晶体积分数明显增大。预测的动态再结晶体积分数与实验结果吻合。

Numerical simulation study on dynamic recrystallization ofAZ31 magnesium alloy during seamless tube extrusion

Based on the stress strain curves obtained by hot compression tests at temperature of 300 ~ 450 ℃ and at strain rate of 0.01 ~ 1 s-1, the empirical dynamic recrystallization models for the semi continuous AZ31 magnesium alloy were developed. The model was applied to the numerical simulation of dynamic recrystallization evolution during seamless tube extrusion of AZ31 magnesium alloy, and was verified by metallographic observation. The results showed that, at certain extrusion speed, the influence of the extruding temperature on the dynamic recrystallization fraction was the most significant. With the increase of the extruding temperature, the volume fraction of dynamic recrystallization increased obviously. The predicted volume fraction of dynamic recrystallization was in excellent agreement with the experimental results.