6063-T5铝合金热变形行为及热加工图研究

Study on hot deformation behavior and hot processing map of 6063-T5 aluminum alloy

采用热模拟试验机对6063-T5铝合金进行轴对称等温热压缩实验,分析热变形过程中热变形参数对其真应力的影响规律,建立自适应系数Arrhenius本构模型和位错密度增长模型,并通过绘制热加工图考查热加工工艺参数对6063-T5铝合金热变形行为的影响.结果表明:随着温度的升高,真应力呈阶梯形下降趋势,材料的软化效果越来越明显;随着应变速率的升高,真应力呈缓慢上升趋势,材料的硬化效果越来越明显;使用决定系数R2作为评估标准构建的自适应系数Arrhenius本构模型与位错密度增长模型可以准确描述热变形参数对6063-T5铝合金热变形行为的影响;使用热加工图进行分析获得了最佳变形温度350~525℃、应变速率0.01~1 s-1.

The thermal simulation testing machine was used to conduct axisymmetric isothermal hot compression experiments on 6063-T5 aluminum alloy.The influence of thermal deformation parameters on the true flow stress was analyzed,and the adaptive coefficient Arrhenius constitutive model and dislocation density growth model were established.The influence of process parameters on the hot deformation behavior of 6063-T5 aluminum alloy was investigated by drawing the hot working diagram.The results showed that,with the increase of temperature,the true stress showed a step-down trend,and the softening effect of the material became more and more obvious.With the increase of strain rate,the true stress increased slowly,and the hardening effect became more and more obvious.The Arrhenius constitutive model which was constructed by using the determination coefficient as the evaluation criterion and the dislocation density growth model can accurately describe the influence of hot deformation parameters on the hot deformation behavior of 6063-T5 aluminum alloy.The hot processing map showed that the optimum deformation temperature and strain rate ranges for the 6063-T5 aluminum alloy were 350~525℃and 0.01~1 s^(-1)respectively.