时效处理对Mg-Y-Gd-Zn-Zr合金中LPSO相演变及性能的影响  

Evolution of LPSO phase and properties of Mg-Y-Gd-Zn-Zr alloy at different aging temperatures

作　　者：任广笑 王超[2,3] 曹喜娟 王凯 王红霞[1,2] 程伟丽 牛晓峰[2] Ren Guangxiao;Wang Chao;Cao Xijuan;Wang Kai;Wang Hongxia;Cheng Weili;Niu Xiaofeng(Shanxi Province Pilot Base for Research and Development of Light Metals and Their Composite Materials and Structured Applications,Shanxi Jianghuai Heavy Industry Co.,Ltd.,Jincheng Shanxi 048000,China;Shanxi Key Laboratory of Advanced Magnesium-Based Materials,College of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan Shanxi 030024,China;Avic Shaanxi Hongyuan Aviation Forging Company Ltd.,Xi'an Shaanxi 710000,China)

机构地区：[1]山西江淮重工有限责任公司,山西省轻金属及其复合材料研发及结构化应用中试基地,山西晋城048000 [2]太原理工大学材料科学与工程学院先进镁基材料山西省重点实验室,山西太原030024 [3]航空工业陕西宏远航空锻造有限公司,陕西西安710000

出　　处：《金属热处理》2024年第9期96-102,共7页Heat Treatment of Metals

基　　金：山西省科技成果转化引导专项(202204021301009,202104021301022);山西省自然科学基金(20210302123135);中央引导地方科技发展资金(YDZJSX20231B003)。

摘　　要：利用OM、SEM、XRD、TEM及性能测试等方法研究了铸态、固溶时效态Mg-6Y-3Gd-3Zn-0.5Zr合金微观组织演变及其对力学性能的影响。结果表明,铸态合金由树枝状α-Mg基体、晶界处连续网状18R-LPSO和Mg_(24)(Gd,Y,Zn)_(5)混合相组成。固溶处理后大部分Mg_(24)(Gd,Y,Zn)_(5)相与少部分18R-LPSO相回溶到基体内。250℃和300℃时效处理后,合金基体内析出了大量层片状14H-LPSO、Mg_(3)(Y,Gd)及Mg_(5)(Y,Gd)相。400℃时效处理后,晶内只析出了14H-LPSO相。铸态合金的抗拉强度和伸长率分别为222.7 MPa和4.1%。时效处理后合金强度均有所下降,伸长率略微上升。400℃峰时效合金由于晶内析出的14H-LPSO数量多、尺寸大,抗拉强度下降最多,相比铸态下降了39 MPa。The microstructural evolution of the Mg-6Y-3Gd-3Zn-0.5Zr alloys in the as-cast,solid solution and aging states and its influence on the mechanical properties were investigated by using OM,SEM,XRD,TEM and property testing methods.The results show that the as-cast alloy consists of dendriticα-Mg matrix with a continuous network of 18R-LPSO and Mg_(24)(Gd,Y,Zn)s mixed phases at the grain boundaries.After solid solution treatment,the most of Mg_(24)(Gd,Y,Zn)s phase and part of the 18R-LPSO phase are dissolved back into the matrix.A large amount of lamellar 14H-LPSO and Mg_(3)(Y,Gd)and Mg_(5)(Y,Gd)phases are precipitated in the matrix after aging at 250℃ and 300℃.Only 14H-LPSO phase is precipitated in the crystals after aging at 400℃.The tensile strength and elongation of the as-cast alloy are 222.7 MPa and 4.1%,respectively.The strength of the alloy decreases and the elongation increases slightly after aging.The alloy peak aged at 400℃ shows the greatest decrease in strength due to the large number and size of 14H-LPSO precipitated in the crystals,and the tensile strength decreases by 39 MPa compared with that of the as-cast state.

关 键 词：Mg-Y-Gd-Zn-Zr合金 LPSO相 热处理 力学性能 

分 类 号：TG156.92[金属学及工艺—热处理]