热机械处理对Al-Cu-Mg合金显微组织和力学性能的调控机理  

Control mechanism of thermo-mechanical treatment on microstructure and mechanical properties of Al-Cu-Mg alloy

作　　者：王琮琳 刘辉新 郑亚亚 王昆 陈志国[1,2] WANG Conglin;LIU Huixin;ZHENG Yaya;WANG Kun;CHEN Zhiguo(School of Materials Science and Engineering,Central South University,Changsha 410083,China;Department of Materials and Environmental Engineering,Hunan University of Humanities,Science and Technology,Loudi 417000,China)

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]湖南人文科技学院材料工程系,娄底417000

出　　处：《中国有色金属学报》2024年第1期50-62,共13页The Chinese Journal of Nonferrous Metals

基　　金：湖南省科技创新计划项目(2022WZ1014);湖南省“双一流学科建设”项目资助。

摘　　要：采用X射线衍射仪(XRD)、透射电子显微镜(TEM)、拉伸力学性能测试以及疲劳裂纹扩展速率测试等手段探究热机械处理工艺对Al-Cu-Mg合金显微组织及宏观性能的影响。结果表明:热机械处理工艺可以使Al-Cu-Mg合金获得良好的强塑性配合,其中,采用25%变形量的固溶热轧+30%变形量的深冷非对称轧制(1.2异速比)+100℃、6 h的人工时效处理时,Al-Cu-Mg合金的伸长率可达10.1%;抗拉强度和屈服强度达到了517.2和448.3 MPa,分别比常规T6态的Al-Cu-Mg合金高74.8和98.6 MPa。热机械处理工艺使合金中出现大量位错缠结及细小S析出相,高强度的Goss织构和大量剪切织构通过影响疲劳裂纹的偏折提升合金的疲劳性能。The effects of novel thermo-mechanical treatment(NTMT)process on the microstructure and macroscopic properties of Al-Cu-Mg alloy were investigated by means of X-ray diffractometer(XRD),transmission electron microscope(TEM),tensile mechanical properties test and fatigue crack growth rate test.The results show that the NTMT process can enable the mechanical properties of Al-Cu-Mg alloy achieve a good combination of strength and plasticity.Using solution hot rolling with 25%reduction,the asymmetric cryorolling with 30%reduction(r2)and the artificial aging at 100℃for 6 h,the elongation is 10.1%,and the tensile strength and yield strength of Al-Cu-Mg alloy are 517.2 MPa and 448.3 MPa,respectively,which are 74.8 MPa and 98.6 MPa higher than those of the conventional T6 Al-Cu-Mg alloy.The NTMT process causes a large number of dislocation tangles and small S phases in the alloy.The high-strength Goss texture and a large number of shear textures improve the fatigue performance of the alloy by affecting the deflection of fatigue cracks.

关 键 词：AL-CU-MG合金 热机械处理 拉伸力学性能 显微组织 疲劳裂纹扩展速率 

分 类 号：TG146.2[一般工业技术—材料科学与工程]