大型环形件用2219铝合金的动态再结晶行为

Dynamic Recrystallization Behavior of 2219 Aluminum Alloy for Large-Scale Rings

选用Gleeble-3500型热模拟试验机在变形温度330~450℃、应变速率10^(-2)\~10 s^(-1)、压缩变形量60%条件下对2219铝合金进行热压缩试验,研究了其在热变形过程中的动态再结晶行为;通过对试验数据进行分析拟合,建立了以Z参数表示的热变形特征参数模型,基于改进Avrami方程的动态再结晶动力学模型以及以变形温度、应变速率表示的再结晶晶粒尺寸模型。结果表明:在低应变速率和高变形温度下,2219铝合金更易于发生动态再结晶;根据动态再结晶动力学模型,最佳热加工条件为应变速率0.1 s^(-1)、温度360℃,此时2219铝合金的动态再结晶程度最高;动态再结晶晶粒尺寸模型预测精度较高,线性相关系数达0.95。

Hot compression tests were conducted on 2219 aluminum alloy at deformation temperatures of 330-450℃,strain rates of 10^(-2)-10 s^(-1),and compression deformation of 60%on a Gleeble-3500 thermal simulation machine,and the dynamic recrystallization behavior during hot deformation was studied.Through analysis and fitting of the experimental data,the thermal deformation characteristic parameter model based on the Z parameter,the dynamic recrystallization kinetic model based on the improved Avrami equation,and the dynamic recrystallized grain size model based on deformation temperatures and strain rates were established.The results show that at a low strain rate and a high deformation temperature,2219 aluminum alloy was more prone to dynamic recrystallization.According to the dynamic recrystallization kinetic model,the optimal hot working conditions were determined as a strain rate of 0.1 s^(-1)and a temperature of 360℃.Under this condition,the dynamic recrystallization degree of 2219 aluminum alloy was the highest.The prediction accuracy of the dynamic recrystallized grain size model was high,and the linear correlation coefficient reached 0.95.