基于热加工图的均匀化态Al-Zn-Mg-Cu合金的热变形行为  

Hot deformation behavior of homogenized Al-Zn-Mg-Cu alloy based on processing map

作　　者：王文浩[1,2] 李波 苏华山[1,2] 孙宇 李哲[2] 瞿发华 Wang Wenhao;Li Bo;Su Huashan;Sun Yu;Li Zhe;Qu Fahua(Key Laboratory of Robot and Intelligent System,China Three Gorges University,Yichang Hubei 443002,China;China College of Mechanical and Power Engineering,China Three Gorges University,Yichang Hubei 443002,China;School of Materials Science and Engineering,Harbin Institute of Technology,Harbin Heilongjiang 150001,China)

机构地区：[1]三峡大学机器人与智能系统宜昌市重点实验室,湖北宜昌443002 [2]三峡大学机械与动力学院,湖北宜昌443002 [3]哈尔滨工业大学材料科学与工程学院,黑龙江哈尔滨150001

出　　处：《金属热处理》2019年第12期170-175,共6页Heat Treatment of Metals

基　　金：湖北省教育厅科学技术研究计划优秀中青年人才项目(Q20161202);水电机械设备设计与维护湖北省重点实验室开放基金(2016KJX04);机器人与智能系统宜昌市重点实验室(三峡大学)开放基金(JXYC00009)

摘　　要：利用Gleeble-3500热模拟试验机进行高温压缩试验,研究均匀化态Al-Zn-Mg-Cu合金在变形温度为380~470℃、应变速率为0.001~1 s-1条件下的热变形行为,建立了合金的流变应力本构方程;基于动态材料模型(DMM)构建了合金的热加工图。研究结果表明:在应变速率一定时,峰值流变应力与变形温度呈现负相关关系;变形温度一定时,峰值流变应力与应变速率表现为较明显的正相关关系,合金平均热变形激活能为159.045 kJ/mol。在高应变速率(0.1~1 s^-1)、低温和高温的变形条件下,大部分区域有明显的失稳,在较高应变速率下功率耗散值较小,而耗散率最大值出现在高温低应变速率条件下。当变形温度为410℃,应变速率为0.01 s-1时,合金中存在明显的动态再结晶组织。结合其微观组织演变规律,确定合金的最佳热工艺参数为440~470℃、应变速率0.001~0.01 s^-1。Hot compression deformation behavior of homogenized Al-Zn-Mg-Cu alloy was studied by means of hot compression tests performed on a Gleeble-3500 thermal mechanical simulator at temperature range of 380-470℃and strain rate of 0.001-1 s^-1,the constitutive equation was obtained and the processing maps were calculated according to the dynamic materials model(DMM).The results show that the flow stress decreases with temperature increasing at a given strain rate,while it increases with strain rate increasing at a given temperature,and the average values of the activation energy are 159.045 kJ/mol.Furthermore,the instability zone of Al-Zn-Mg-Cu alloy is mainly distributed in the high strain rates(0.1-1 s-1)and exclusion of moderate temperature region,the efficiency of power dissipation obtains the higher values at high strain rate and the maximum power dissipation rate is in high temperature and low strain rate area.When the deformation temperature is 410℃and the strain rate is 0.01 s-1,there is obvious dynamic recrystallization structure in the studied alloy.According to the microstructure evolution,the optimum processing parameters can be obtained at the temperature range of 440-470℃and the strain rate range of 0.001-0.01 s^-1.

关 键 词：AL-ZN-MG-CU合金 热激活能 本构方程 热加工图 

分 类 号：TG151[金属学及工艺—热处理]