应变影响的AZ31B镁合金流动应力预测模型研究

Research on the strain-effect flow stress prediction model of AZ31B magnesiumSalloy

摘要:

本文采用热压缩试验获得了铸态AZ31B镁合金高温变形时的流变曲线，分析了变形温度和应变速率对流动应力的影响。结果表明：峰值应变随着应变速率增加和温度减小而增大，减小应变速率、适当提高变形温度对材料的动态回复和再结晶是有利的。利用多元回归分析建立了流动应力预测模型，该模型可以描述流动应力的应变敏感性，经验证发现使用其预测流动应力具有较高精度，相关系数高达0.9926，能较好地描述铸态AZ31B镁合金在热变形过程的流动行为。

Abstract:

In this paper, the hot compression tests were carried out, the true stress-strain curves were obtained during AZ31B cast rod deformation, and the effects of deformation temperatures and strain rates on flow stress were analyzed. It was found that the peak strain increased with the increasing strain rate and decreasing deformation temperature, and it is advantageous for dynamic recovery and recrystallization to reduce strain rate and properly raise deformation temperature. Moreover, the flow stress prediction model, which was established by means of multiple regression analysis can illustrate the strain-sensitivity of flow stress. Furthermore, it is investigated that the correlation?coefficient of predicted and experimental values is up to 0.9926, indicating that this model is more accurate in terms of predicting the flow stress of as-cast AZ31B magnesium?alloy and can better?describe its flow behavior during hot deformation.