直接时效对激光增材制造Al-Cu-Mg-Li-Sc-Zr合金组织与性能的影响  

Effect of direct aging on microstructure and properties of Al-Cu-Mg-Li-Sc-Zr alloy prepared by laser additive manufacturing

作　　者：吴祖胜 刘燕[1] 高建宝 章媛洁 张金良[1] 宋波[1] 史玉升[1] WU Zu-sheng;LIU Yan;GAO Jian-bao;ZHANG Yuan-jie;ZHANG Jin-liang;SONG Bo;SHI Yu-sheng(State Key Laboratory of Materials Processing and Die&Mould Technology,Huazhong University of Science and Technology,Wuhan 430074,China;School of Mechanical&Electrical Engineering,Wuhan Institute of Technology,Wuhan 430205,China)

机构地区：[1]华中科技大学材料成形与模具技术全国重点实验室,湖北武汉430074 [2]武汉工程大学机电工程学院,湖北武汉430205

出　　处：《材料热处理学报》2024年第12期48-57,共10页Transactions of Materials and Heat Treatment

基　　金：国家重点研发计划(2023YFB4604800);国家自然科学基金(52275331,52201041,52401047);湖北省重点研发计划(2022BAA011);中国博士后科学基金(2021M690061,2023M741244)。

摘　　要：采用光学显微镜、扫描电镜、透射电镜、显微硬度计和和万能材料试验机等研究了直接时效对激光选区熔化制备的Al-Cu-Mg-Li-Sc-Zr合金显微组织和力学性能的影响。结果表明:经直接时效热处理后,Al-Cu-Mg-Li-Sc-Zr合金中析出了大量针状和球形颗粒析出相,其中粗针状析出相为Al_(2)CuMg相,细针状析出相为Al_(2)CuLi相,球形颗粒为Al_(3)(Sc,Zr)相;随着时效时间延长,合金强度呈现先升高后降低的变化趋势,伸长率呈下降趋势;合金的最佳直接时效工艺为320℃×6 h,此时,合金的抗拉强度和屈服强度分别为(628±5)MPa和(611±7)MPa,伸长率为(1.44±0.06)%,硬度为(168±1)HV;拉伸试样断口形貌表明直接时效后合金的断裂机制为脆性断裂。Effect of direct aging on microstructure and mechanical properties of Al-Cu-Mg-Li-Sc-Zr alloy prepared by selective laser melting was studied using optical microscope,scanning electron microscopy,transmission electron microscopy,microhardness tester,and universal material testing machine.The results show that after direct aging heat treatment,a large number of needle-like and spherical precipitates are precipitated in the Al-Cu-Mg-Li-Sc-Zr alloy,among which the coarse needle-like precipitate is Al_(2)CuMg phase,the fine needle-like precipitate is Al_(2)CuLi phase,and the spherical particle is Al_(3)(Sc,Zr)phase.As the aging time increases,the alloy strength shows a trend of first increasing and then decreasing,while the elongation shows a decreasing trend.The optimal direct aging process for the alloy is 320℃×6 h,and the tensile strength and yield strength of the alloy are(628±5)MPa and(611±7)MPa,respectively,with an elongation of(1.44±0.06)%and a hardness of(168±1)HV.The fracture morphology of the tensile specimen shows that the fracture mechanism of the alloy after direct aging is brittle fracture.

关 键 词：激光选区熔化 Al-Cu-Mg-Li-Sc-Zr合金 直接时效 显微组织 力学性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]