挤压态6082铝合金热加工图及显微组织研究

Processing map and microstructure of extruded 6082 aluminum alloy

用Gleeble3500热模拟试验机对挤压态6082铝合金进行等温恒应变率压缩试验,变形温度为350~500℃,应变率为0.01~7.5 s^-1,获得不同变形条件下的真应力-真应变曲线,建立本构方程和热加工图,并对不同条件下显微组织进行分析。结果表明:挤压态6082铝合金为正应变率敏感材料,该材料热变形软化机制主要为动态回复,热变形失稳主要是析出相聚集导致局部流变失稳,计算得到该合金的热变形激活能为175.17 kJ/mol,安全加工区主要分布在375~500℃,0.001~0.5 s^-1,随应变增加安全加工区变化很小。

Isothermal and constant strain rate compression experiments of the extruded 6082 aluminum alloy were investigated by the Gleeble3500 thermal simulation testing machine.The deformation temperature was 350-500℃,and the strain rate was 0.01-7.5 s^-1.The true stress-true strain curves under different deformation conditions were obtained.The constitutive equation and thermal processing map were established,and the microstructure under different conditions was analyzed.The results show that the as-extruded 6082 aluminum alloy is a positive strain rate sensitive material.The thermal deformation softening mechanism of the material is mainly dynamic recovery,and the thermal deformation instability is mainly caused by the local rheological instability caused by precipitation phase aggregation.The thermal deformation activation energy of the alloy was calculated to be 175.17 kJ/mol.The safe processing area is mainly distributed at 375-500℃,0.001-0.5 s^-1,and the safe processing area changes little with the increase of strain.