Cu质量分数对Al-1.0Mg-1.0Si-0.6Mn合金显微组织和性能的影响  

Effect of Cu mass fraction on microstructures and properties of Al-1.0Mg-1.0Si-0.6Mn alloys

作　　者：刘名鑫 邓运来[1,3] 张臻 唐建国[1,3] LIU Mingxin;DENG Yunlai;ZHANG Zhen;TANG Jianguo(School of Materials Science and Engineering,Central South University,Changsha 410083,China;Light Alloy Research Institute,Central South University,Changsha 410083,China;State Key Laboratory of High Performance Complex Manufacturing,Central South University,Changsha 410083,China)

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083 [2]中南大学轻合金研究院,湖南长沙410083 [3]中南大学高性能复杂制造国家重点实验室,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2020年第2期309-318,共10页Journal of Central South University:Science and Technology

基　　金：国家重点研发计划项目(2016YFB0300901);国家自然科学基金资助项目(51705539)~~

摘　　要：利用硬度测试、室温拉伸实验、晶间腐蚀实验、电化学腐蚀实验、SEM和TEM等方法,研究Cu质量分数对Al-1.0Mg-1.0Si-0.6Mn合金显微组织与性能的影响。研究结果表明:随着Al-1.0Mg-1.0Si-0.6Mn合金中Cu质量分数由0.01%逐渐增加至1.12%,其达到峰值时效所需时间逐渐减少,且峰值时效(T6态)硬度明显增加;随着Cu质量分数的增加,峰时效状态合金的抗拉强度由357.7 MPa逐渐增加至452.2 MPa,抗拉强度提升94.5 MPa,这是因为随着Cu质量分数增加,晶内析出相数量逐渐增多且尺寸逐渐减小,使得沉淀强化效果逐渐增强;Cu质量分数增加使粗大相AlFeMnSi的数量逐渐增加,腐蚀电流密度显著增大,合金的断后伸长率和抗晶间腐蚀性能呈下降趋势。The effect of Cu mass fraction on the microstructures and properties of Al-1.0Mg-1.0Si-0.6Mn alloy was studied by means of hardness test,tensile test,intergranular corrosion test,electrochemical corrosion test,SEM and TEM.The results show that the time required to reach peak aging decreases gradually and the hardness in T6 status increases obviously with the increase of Cu mass fraction.The tensile strength increases from 357.7 MPa to 452.2 MPa,i.e.the strength increases by 94.5 MPa.The reason is that the number of precipitates in the alloys increases and the size of precipitates becomes smaller gradually with the increase of Cu mass fraction,which enhances the precipitation-strengthening effect.However,the number of the coarse phases such as AlFeMnSi increases gradually and the corrosion current density increases dramatically.The elongation rate after fracture and the intergranular corrosion resistance of the alloys show a descending trend.

关 键 词：Cu质量分数 Al-1.0Mg-1.0Si-0.6Mn合金 抗拉强度 析出相 抗晶间腐蚀性能 粗大相 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG115.5[金属学及工艺—金属材料]