时效时间对7175铝合金组织和力学性能的影响  

Effect of aging time on microstructure and mechanical properties of 7175 aluminum alloy

作　　者：汲庆涛 孙有政 杨慧 赵忠超 史晓明 Ji Qingtao;Sun Youzheng;Yang Hui;Zhao Zhongchao;Shi Xiaoming(National Engineering Research Center for Plastic Working of Aluminium Alloys,Shandong Nanshan Aluminium Co.,Ltd.,Longkou Shandong 265713,China;Shandong Nanshan Academy of Science and Technology Co.,Ltd.,Longkou Shandong 265713,China;Yantai Nanshan University,Longkou Shandong 265713,China)

机构地区：[1]山东南山铝业有限公司国家铝合金压力加工工程技术研究中心,山东龙口265713 [2]山东南山科学技术研究院有限公司,山东龙口265713 [3]烟台南山学院,山东龙口265713

出　　处：《金属热处理》2024年第9期242-246,共5页Heat Treatment of Metals

摘　　要：采用光学显微镜(OM)、扫描电镜(SEM)、透射电镜(TEM)、维氏硬度计和万能拉伸试验机系统研究了7175铝合金在120℃时效过程中的微观组织变化和力学行为。结果表明,经固溶和时效处理后,7175铝合金组织为典型纤维状组织,未产生明显再结晶,晶粒形貌和第二相在时效过程中无明显差异。随着时效时间的延长,晶界处的析出相尺寸逐渐变大,晶内析出相粒径变大,平均粒径由5.87 nm变为8.38 nm。7175铝合金在120℃时效时,硬度在16 h达到峰值,峰值硬度为196.5 HV,16 h时晶内析出相数量多、细小、分布均匀,有效提高了合金的硬度。同时,合金在10~16 h时效时,合金的屈服强度迅速增大,从471 MPa迅速增长到490 MPa,时效时间大于16 h后,屈服强度变化趋近于平缓。Microstructure and mechanical behavior of the 7175 aluminum alloy during aging process at 120℃for diferent time were systematically studied by means of OM,SEM,TEM,Vickers hardness tester and universal tensile testing machine.The results show that after solution treatment and aging,the microstructure of 7175 aluminum alloy is typical fibrous structure,with no obvious recrystallization occurring,and there is no obvious difference in grain morphology and second phase during aging.As the aging time increases,the size of precipitated phase at the grain boundary gradually increases,the particle size of precipitated phase in the grain increases,with the average particle size changing from 5.87 nm to 8.38 nm.When aged at 120℃,the hardness of 7175 aluminum alloy reaches the peak at 16 h,and the peak hardness is 196.5 HV.When aged at 120 C for 16 h,the precipitated phase in the grain is much quantity,small and evenly distributed,which effectively improves the hardness of the alloy.At the same time,the yield strength of the alloy increases rapidly from 471 MPa to 490 MPa,when the aging time is 10-16 h,and the change of yield strength tends to be flat when the aging time is greater than 16 h.

关 键 词：铝合金 时效时间 微观组织 析出相 硬度 

分 类 号：TG146.2[一般工业技术—材料科学与工程]