Mg-1.4Gd-1.2Y-0.4Zn-0.1Zr合金挤压板材的组织与力学性能  

Microstructure and Mechanical Properties of Mg-1.4Gd-1.2Y-0.4Zn-0.1Zr Alloy Extruded Sheet

作　　者：马晗 黄正华 张浩 姚祎[1,2] 张忠明 徐春杰[1] 康跃华[2] 王顺成 李卫荣 MA Han;HUANG Zhenghua;ZHANG Hao;YAO Yi;ZHANG Zhongming;XU Chunjie;KANG Yuehua;WANG Shuncheng;LI Weirong(School of Materials Science and Engineering,Xi'an University of Technology,Xi'an 710048,China;Guangdong-Hong Kong Joint Research and Development Center on Advanced Manufacturing Technology for Light Alloys,Guangdong Institute of Materials and Processing,Guangzhou 510650,China;Dongguan EONTEC Co.,Ltd.,Dongguan 523662,China)

机构地区：[1]西安理工大学材料科学与工程学院,陕西西安710048 [2]广东省材料与加工研究所粤港轻合金先进制造技术联合研发中心,广东广州510650 [3]东莞宜安科技股份有限公司,广东东莞523662

出　　处：《热加工工艺》2021年第16期108-111,共4页Hot Working Technology

基　　金：广东省科学院发展专项资金项目(2019GDASYL-0203002,2018GDASCX-0966);东莞市核心技术攻关重点项目(2019622134013);广东省自然科学基金项目(2016A030313802);陕西省重点研究与发展项目(2017GY-135);广州市科学研究专项项目(20170701039)。

摘　　要：制备了Mg-1.4Gd-1.2Y-0.4Zn-0.1Zr(at%)合金挤压板材,并进行了时效处理。采用XRD、OM、SEM和TEM分析了不同状态合金的相组成和微观组织,并测试了其室温硬度和拉伸力学性能。结果表明,铸态组织由α-Mg基体、Mg_(3)(RE,Zn)共晶相、长周期堆垛有序(LPSO)结构以及Mg-RE颗粒组成。经固溶处理后,晶界处的Mg_(3)(RE,Zn)共晶相固溶于基体中,并且富集的RE和Zn元素从晶粒内部的堆垛层错处析出。经热挤压后,板材组织呈现典型的双峰晶粒分布,粗大未变形晶粒周围分布大量破碎的LPSO结构,且这些第二相的分布限制了动态再结晶晶粒长大,其抗拉强度、屈服强度和伸长率分别为380 MPa、327 MPa和8.0%。再经200℃时效48 h后,基体内部析出大量纳米尺度的β’相,合金的抗拉强度和屈服强度分别提高至435 MPa和380 MPa,伸长率降为5.0%。Mg-1.4 Gd-1.2 Y-0.4 Zn-0.1 Zr(at%) alloy extruded sheet was prepared, and the aging treatment was carried out.The phase composition and microstructure of the alloy in different states were analyzed by XRD, OM, SEM and TEM. The hardness and tensile mechanical properties at room temperature were tested. The results show that, the cast structure is composed of α-Mg matrix, Mg_(3)(RE, Zn) eutectic phase, long-period stacking ordered(LPSO) structure and Mg-RE particles.After solid solution treatment, the eutectic phase of Mg_(3)(RE, Zn) at the grain boundary is dissolved in the matrix, and the enriched RE and Zn elements precipitate from the stacking fault inside the grain. After hot extrusion, the plate microstructure presents a typical bimodal grain distribution, and a large number of broken LPSO structures are distributed around the coarse and undeformed crystal grains, and the distribution of the second phases limits the growth of the dynamic recrystallization grain, the tensile strength, yield strength and elongation are380 MPa, 327 MPa and 8.0%, respectively. After aging at200 ℃ for 48 h, a large number of nano-scale β’ phases are precipitated in the matrix, and the tensile strength and yield strength of the alloy are increased to 435 MPa and 380 MPa,respectively, and the elongation is reduced to 5.0%.

关 键 词：高强镁合金 热挤压 热处理 微观组织 力学性能 

分 类 号：TG166.4[金属学及工艺—热处理]