铸态高强铝合金热变形流变应力行为的研究

Research on Flow Stress Behavior during Hot Deformation of As-cast High Strength Aluminum Alloy

文中采用热力模拟试验方法对新型铸态高强铝合金试样进行了热压缩实验，研究了新型高强铝合金在变形温度为300-420℃、应变速率为0.01-1 s-1条件下压缩变形程度达到50%的流变应力变化规律。研究表明，该合金热变形应力—应变曲线呈现动态回复型曲线；流变应力随变形温度的升高而降低，随应变速率的增大而增大；热变形激活能为269.985 kJ/mol，应力指数为7.0097。

Hot compression tests with constant temperature and strain rate were conducted by means of the thermo-mechani-cal simulation method at temperatures in the range of 300 ℃~420 ℃, strain rates in the range of 0.01 s-1~1 s-1 and high re-duction up to 50% of new as-cast high strength aluminum alloy. Flow stress behaviors were analyzed. The results indicate that flow stress increases with increase of temperature and decrease of strain rate. Hot deformation stress-strain curves have characteristics of dynamic recovery flow stress curves. The values of hot deformation activated energy and stress exponent are 269.985 kJ/mol and 7.009 7 respectively.