摘要
采用光学显微镜、透射电镜组织分析手段和室温拉伸、电导率、剥落腐蚀、疲劳极限性能测试方法,研究了二级时效温度对7B04-T74合金2 mm厚薄板组织与性能的影响。结果表明:二级时效温度由165℃逐渐升高至175℃时,7B04-T74合金晶粒组织特征没有明显变化,晶内析出相数量减少且尺寸增加,晶界析出相粗大且断续分布;7B04-T74态铝合金薄板的室温拉伸抗拉强度、屈服强度明显降低,其伸长率无明显变化,电导率明显提升,剥落腐蚀级别无明显变化趋势。通过对比不同二级时效温度下7B04铝合金的组织与性能测试结果可知,7B04合金2 mm厚薄板由退火状态到T74状态的最优二级时效温度为173℃。
Effect of secondary aging temperature on microstructure and properties of the 2 mm thickness 7B04-T74 alloy sheet was studied by means of optical microscope,transmission electron microscope,tensile test,conductivity test,exfoliation corrosion test and fatigue limit test.The results show that when the secondary aging temperature gradually increases from 165℃to 175℃,the grain structure characteristics of the 7B04-T74 alloy have no obvious change,the number of precipitates within the grain decreases but their size increases,and the precipitates at grain boundary are coarse and intermittent distribution.Tensile strength and yield strength of the 7B04-T74 aluminum alloy sheet at room temperature are significantly reduced,the elongation has no obvious change,the conductivity is significantly increased,and the exfoliation corrosion grade has no obvious change trend.By comparing the structure and properties of the 7B04 aluminum alloy at different secondary aging temperatures,it comes to the conclusion that the optimal secondary aging temperature for 2 mm thickness 7B04 alloy sheet from annealing state to T74 state is 173℃.
作者
姚泽
钟立伟
卢影峰
冯朝辉
陈军洲
Yao Ze;Zhong Liwei;Lu Yingfeng;Feng Zhaohui;Chen Junzhou(Shenyang Aircraft Corporation,Shenyang Liaoning 110034,China;Institute of Aluminum Alloy,AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China;Beijing Engineering Research Center of Advanced Aluminum Alloys and Applications,AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2021年第10期86-91,共6页
Heat Treatment of Metals
基金
国家自然科学基金(51374187)。
关键词
7B04铝合金
时效
组织
性能
7B04 aluminum alloy
aging
microstructure
properties
