Al-Mg-Sc合金热压缩变形的流变应力行为

来源期刊：中南大学学报(自然科学版)2009年第4期

论文作者：潘清林 张小刚 李文斌 刘晓艳 张心明 郭昀抒

文章页码：926 - 931

关键词：Al-Mg-Sc合金；热压缩变形；流变应力；本构方程

Key words：Al-Mg-Sc alloy; hot compression; flow stress; constitutive equation

摘    要：采用热模拟试验对1种Al-Mg-Sc合金进行等温热压缩实验，研究该合金在变形温度为300~450 ℃，应变速率0.001~1 s^-1条件下的热压缩变形流变应力行为。结果表明：该Al-Mg-Sc合金在变形温度为300 ℃，应变速率0. 01~1 s^-1的条件下，流变应力开始随应变增加而增大，达到峰值后趋于平稳，表现出动态回复特征；而在其他条件下，应力达到峰值后随应变的增加而逐渐下降，表现出动态再结晶特征。应变速率和流变应力之间满足指数关系，温度和流变应力之间满足Arrhenius关系，通过线性回归分析计算出该材料的应变硬化指数n以及变形激活能Q，获得该铝合金高温条件下的流变应力本构方程。

Abstract: The flow stress behavior of the Al-Mg-Sc alloy during hot compression deformation conditions was studied by isothermal hot compression with thermal simulation test at deformation temperature range of 300-450 ℃ and strain rate range of 0.001-1 s^-1. The experimental results indicate that the flow stress of Al-Mg-Sc alloy increases with increasing strain and tends to be constant after a peak value at 300 ℃ and strain rates range of 0.01-1 s^-1, showing dynamic recovery. The flow stress falls down after a peak value with the increase of strain in other conditions, showing dynamic recrystallization. A hyperbolic sine relationship is found to correlate well the flow stress with the strain rate, and an Arrhenius relationship with the temperature. The strain hardening coefficient n and deformation activation energy Q are evaluated by linear regression analysis. And the flow stress constitutive equation of the alloy during hot compression is obtained.

基金信息：国家“863”计划项目