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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。
The finite element software DEFORM-3D was used to simulate the channel angular extrusion (ECAP) process of 7075 aluminum alloy. The load change, deformation behavior and equivalent stress-strain distribution under different friction conditions were analyzed. The crystallization model predicts the microstructure evolution. The results show that as the friction coefficient increases, the peak value of load increases or even increases exponentially, and the fluctuation of load value aggravates. The “end effect” of specimen decreases, and the distribution of equivalent stress and strain is not uniform. With the increase of the extrusion pass, the grains in the zone are continuously refined. The contact area between the sample and the passage forms fine grains. After 4 passes, the grain friction coefficient of the stable deformation zone is 0.1 when the friction coefficient is 0.4 When small.