复合热处理对7075铝合金组织和力学性能的影响  

Effect of Combined-heat Treatment on Microstructure and Mechanical Properties of 7075 Aluminum Alloy

作　　者：张亮[1] 李茂军 司乃潮[2] ZHANG Liang;LI Maojun;SI Naichao(School of Intelligent Manufacturing, Changzhou Vocational Institute of Engineering,Changzhou 213164,China;School of Materials Science and Engineering, Jiangsu University,Zhenjiang 212013, China)

机构地区：[1]常州工程职业技术学院智能制造学院,江苏常州213164 [2]江苏大学材料科学与工程学院,江苏镇江212013

出　　处：《有色金属工程》2019年第9期93-98,共6页Nonferrous Metals Engineering

基　　金：江苏高校品牌专业建设工程资助项目(PPZY2015C235);江苏省大学生创新创业训练计划项目(201813102019X)~~

摘　　要：采用光学显微镜(OM)、扫描电子显微镜(SEM)、布氏硬度计、室温拉伸测试与ImageJ图像处理软件等手段,研究了复合热处理对7075铝合金微观组织与力学性能的影响。结果表明,与T6处理相比,固溶+深冷12h+时效复合热处理工艺对7075铝合金组织与性能提高作用明显,在其延伸率基本保持不变的基础上,抗拉强度与硬度分别提升了18.6%与20.43%;深冷过程中温度剧烈变化带来的应力细化了合金的晶粒,同时降低了Al基体的固溶度,促进原子析出形成更多GP区,为时效过程中析出相的孕育提供了更多驱动力,增加了合金的析出相强化效果,进一步提升合金的力学性能。The microstructure and mechanical properties of 7075 aluminum alloy after combined-heat treatment were investigated by Optical Microscope (OM), Scanning Electron Microscope (SEM), Brinell hardness tester, room temperature tensile test, and ImageJ image processing software. The results show that compared with T6 treatment, the solid solution+12 h cryogenic+aging composite heat treatment process has obvious effect on the microstructure and properties of 7075 aluminum alloy. Under the condition that the elongation is basically unchanged,.the tensile strength and hardness increase by 18.6% and 20.43%, respectively. The stress caused by the cryogenic process refines the grain of the alloy during the deep cooling process, while the low temperature reduces the solid solubility of the Al matrix, and promotes the precipitation of atoms to form more GP zones, which is in the process of aging. The precipitation of the precipitated phase provides more driving force, increases the effect of precipitation phase strengthening effect of the alloy, and further improves the mechanical properties of the alloy.

关 键 词：7075铝合金 复合热处理 显微组织 析出强化 

分 类 号：TG156[金属学及工艺—热处理] TG166.3[金属学及工艺—金属学]