稀土元素La、Ce对Al-7Si-0.4Cu-1.0Fe压铸铝合金组织和性能的影响  

Effect of Rare Earth Elements La and Ce on Microstructure and Properties of Al-7Si-0.4Cu-1.0Fe Die Casting Aluminum Alloy

作　　者：甘培原 韦德仕 韦世强 秦文忠 彭健飞 曾杰 GAN Peiyuan;WEI Deshi;WEI Shiqiang;QIN Wenzhong;PENG Jianfei;ZENG Jie(Chinalco Guangxi Nonferrous Rare Earth Development Co.,Ltd.,Nanning Guangxi 530024,China;Guangxi Guorui Rare Scandium New Material Technology Co.,Ltd.,Chongzuo Guangxi 532100,China;School of Metallurgy and Environment,Central South University,Changsha Hunan 410083,China)

机构地区：[1]中铝广西有色稀土开发有限公司,广西南宁530024 [2]广西国瑞稀钪新材料科技有限公司,广西崇左532100 [3]中南大学冶金与环境学院,湖南长沙410083

出　　处：《上海金属》2023年第3期13-19,共7页Shanghai Metals

基　　金：广西创新驱动发展专项(桂科AA17204036);广西重点研发计划(2021AB17090)。

摘　　要：研究了稀土元素La、Ce对Al-7Si-0.4Cu-1.0Fe压铸铝合金微观组织、导热性能及力学性能的影响。结果表明:添加稀土元素La、Ce能够细化合金α-Al晶粒,其形态从枝晶转变为胞状晶,平均二次枝晶臂间距从16.3μm减小至11.2μm,降低了31.3%;共晶Si明显细化变质,平均面积从1.4μm^(2)降低至0.4μm^(2),平均纵横比从1.91降低至1.13。稀土元素La、Ce在合金中分布均匀,未发现明显的含La、Ce的金属间化合物。相较于未添加稀土合金,添加0.1%(质量分数,下同)La和0.1%Ce的合金热导率从140.33 W/(m·K)提高至159.68 W/(m·K),抗拉强度从176.1 MPa提高至213.6 MPa,断后伸长率从2.78%提高至6.62%,分别提高了13.8%、21.3%和238.1%。Effects of rare earth elements La and Ce on microstructure,thermal conductivity and mechanical properties of Al-7Si-0.4Cu-1.0Fe die casting aluminum alloy were investigated.The results showed that with the addition of La and Ce to the alloys,(a)theα-Al grains were refined,and their morphology transformed from dendrite to cellular-like,while the mean secondary dendrite arm spacing was reduced by 31.3%(from 16.3 to 11.2μm);(b)the eutectic Si phases were also refined and modified,the average area decreased from 1.4 to 0.4μm^(2),and the average aspect ratio decreased from 1.91 to 1.13.The rare earth elements La and Ce distributed uniformly in the alloys,and no obvious La or Ce-containing intermetallics were found.Compared with the alloy without rare earth,the thermal conductivity of the alloy with 0.1%(mass fraction,the same below)La and 0.1%Ce increased by 13.8%(from 140.33 to 159.68 W/(m·K)),the tensile strength increased by 21.3%(from 176.1 to 213.6 MPa),and the elongation increased by 238.1%(from 2.78%to 6.62%),respectively.

关 键 词：压铸铝合金 La CE 热导率 力学性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]