7055铝合金的热变形行为及挤压工艺研究

Study on Hot Deformation Behavior and Extrusion Process of 7055 Aluminum Alloy

采用Gleeble热模拟压缩试验研究了7055铝合金的热变形行为和组织演变规律,获得了变形温度和应变速率理论参数,实现了工业生产验证。结果表明:当温度在380~460℃范围内,应变速率在0.001~0.1s-1间时,合金表现为稳态流变;应变速率为1s-1时,合金发生流变硬化;在此变形参数区间的组织演变以动态回复为主。当变形温度为460℃、应变速率为10s-1时,合金发生严重的塑性失稳。基于热模拟试验与组织分析提出了热变形工艺理论参数,并在工厂进行了挤压验证,最终确定了7055合金较佳的挤压温度为420~440℃,挤压速率为0.3~0.7 m/min。

Hot deformation behavior and microstructure evolution of 7055 aluminum alloy were studied using Gleeble hot compres⁃sion test.The theory parameters of deformation temperature and strain rates were obtained,torealize the industrial production verifica⁃tion.The result shows that the alloy exhibits stable flow within the range of 380℃~460℃temperature and strain rates of 0.001s-1~0.1s-1,while flow hardening at 1s-1;the microstructure evolution in this deformation parameter interval is dominated by dynamic recovery.As the condition of 460℃and 10s-1,a serious plastic unstability appear,which is a undesirable case during hot deformation.According to the hot simulation compression,microstructure analysis,extrusion were verified in factory producing.Finally,a good extrusion process was determined as temperature of 420~440℃and extrusion speed of 0.3~0.7m/min。