【摘要】 采用有限元软件DEFORM-3D对7075铝合金等通道角挤压(ECAP)过程进行数值模拟,分析了不同摩擦条件下载荷变化、变形行为以及等效应力应变分布情况,并利用7075铝合金动态再结晶模型对微观组织变化过程进行了预测。结果表明,随着摩擦因数增大,载荷峰值明显增大甚至成倍增长,且载荷值波动加剧,试样"端部效应"减弱,等效应力应变分布不均匀;试样中部稳定变形区晶粒随挤压道次增多而不断细化,试样与通道接触部位形成晶粒细小区,经过4道次挤压后,摩擦因数为0.4时稳定变形区的晶粒比摩擦因数为0.1时的细小。更多还原

【Abstract】 The equal channel angular pressing (ECAP) for 7075aluminum alloy was simulated with different friction factors using the finite element software DEFORM-3D.The pressing load,deformation rate as well as effective stress and strain distribution were analyzed,and the change of microstructure of7075aluminum alloy during ECAP was predicted using the dynamic recrystallization model.The results show that,with the increase of the friction factor,the peak load is significantly increased and even grow exponentially accompanying with the sharp fluctuation of load.Besides,the"end effect"of sample is weakened and the effective stress and strain distribution exhibit uneven.The grains of the stable deformation zone in the central of sample are constantly refined with the extrusion passes increases,and the fine grain area is generated in the sample contact with the channel.In addition,the grains of the stable deformation zone with frictional coeffiaent of 0.4are finer than those with 0.1after four passes extrusion.更多还原