稀土Y对Al-8%Mn合金微观组织和性能的影响  

Effect of rare earth yttrium addition on the microstructure and properties of Al-8%Mn alloy

作　　者：刘建军[1] 吕姝玥 曾宝根 兰晔峰[1] 李庆林[1] LIU Jian-jun;LÜ Shu-yue;ZENG Bao-gen;LAN Ye-feng;LI Qing-lin(College of Materials Science and Engineering, Lanzhou Univ. of Tech., Lanzhou 730050, China)

机构地区：[1]兰州理工大学材料科学与工程学院,甘肃兰州730050

出　　处：《兰州理工大学学报》2021年第1期11-15,共5页Journal of Lanzhou University of Technology

基　　金：国家自然科学基金(51561021)。

摘　　要：采用光学显微镜、扫描电子显微镜、电子探针和X射线衍射仪,研究了Al-8%Mn合金熔体中添加稀土Y质量分数对合金微观组织的作用机制,并分析了稀土Y添加量对合金力学性能和耐蚀性能的影响规律.结果表明:稀土Y能有效细化Al-8%Mn合金中的Al_(6)Mn化合物相和α-Al相.当Y的添加质量分数为3%时,细化效果最佳,使Al6Mn相的形貌由粗大板条状和块状转变为细小块状,平均尺寸由未细化前的67.4μm减小到36.5μm,α-Al由粗大的柱状晶细化成等轴晶,其平均尺寸减小至48μm.稀土Y添加后Al-8%Mn合金的抗拉强度和延伸率分别由组织未细化前的126 MPa和1.47%增加到141 MPa和2.26%,分别提高了12.0%和76.9%.此外,在30 g NaCl+10 mL HCl+1 L H_(2)O溶液中的腐蚀研究表明,随着Al-8%Mn合金中稀土Y添加量的增加,合金的抗蚀性能逐渐变差.The optical microscope,SEM,electron probe and XRD were used respectively in this research to investigate the dominant mechanism of rare earth Y added in Al-8%Mn alloy melt on microstructure of the alloy.The effect of amount of rare earth Y on the mechanical properties and corrosion resistance of the alloy was analyzed as well.Our results show clearly that the addition of rare earth Y can refine Al6Mn compounds andα-Al phases in Al-8%Mn alloy during alloy solidification.Moreover,after adding 3wt.%Y to Al-8%Mn alloy melt,the refining efficiency caused by Al6Mn andα-Al phases is most significant.The morphology of Al6Mn phases changes from coarse lath to small piece and blocky,and the average size of Al_(6)Mn reduces from 67.4μm to 36.5μm.Hence,the morphology ofα-Al phase transfers from coarse columnar crystal to equiaxed crystal,and the average size decreases to 48μm when 3wt.%Y is added to Al-8%Mn alloy melt.Both the ultimate tensile strength and elongation of Al-8Mn-3wt.%Y alloy are improved up to 141.37 MPa and 2.26%respectively.In the end,the addition of rare earth reduces the intergranular corrosion resistance of the alloy in etching solution(30 g NaCl+10 mL HCl+1 L H_(2)O).

关 键 词：AL-MN合金 Al6Mn α-Al 力学性能 抗蚀性能 

分 类 号：TG146[金属学及工艺—金属材料]