Mg含量对Al-9Si-xMg合金组织和性能的影响  

Effect of Mg content on microstructure and properties of Al-9Si-xMg alloy

作　　者：杨蕾 周鹏飞 翁文凭 许朝阳 杨东坤 唐迪 范卫忠 长海博文 YANG Lei;ZHU Peng-fei;WENG Wen-ping;XU Zhao-yang;YANG Dong-kun;TANG Di;FAN Wei-zhong;HIRMI Naguami(School of Materials Science and Engineering,Beijing University of Aeronautics and Astronautics,Beijing 100191,China;School of Iron and Steel,Soochow University,Suzhou 215021,China;Guangdong Hongbang Metal Aluminum Co.,Ltd.,Guangzhou 511300,China)

机构地区：[1]北京航空航天大学材料科学与工程学院,北京100191 [2]苏州大学沙钢钢铁学院,江苏苏州215021 [3]广东鸿邦金属铝业有限公司,广东广州511300

出　　处：《轻合金加工技术》2020年第11期14-19,共6页Light Alloy Fabrication Technology

摘　　要：采用水冷铜模浇铸不同Mg含量的Al-9Si-xMg合金试样,通过室温拉伸、激光散射法测试合金试样力学性能和热传导性能,结合OM/SEM结果分析Mg含量对Al-9Si-xMg合金铸态组织和性能的影响。结果表明:Al-9Si-xMg合金铸态组织由初生α-Al和共晶硅组成,Mg能改善合金共晶硅相组织均匀性,当w(Mg)=0.4%~0.71%时,共晶硅的平均长度从68μm左右降低到61μm左右;共晶硅相组织均匀性得到提升,这种硅相的组织结构有利于自由电子在初生α-Al和共晶硅之间自由运动,合金热导率下降幅度趋于平缓。在较快冷却速率条件下,Mg全部以固溶形式进入Al基体,提高初生α-Al的强度。Al-9 Si-xMg alloy samples with different Mg contents were cast by the watercooled copper mold.The mechanical properties and thermal conductivity of the alloy samples were tested by room temperature tensile test and laser scattering method.The effect of Mg content on the as-cast microstructure and properties of Al-9 Si-xMg alloy was analyzed by OM/SEM.The results show that the as-cast microstructure of Al-9Si-xMg alloy is composed of primary α-Al and eutectic silicon.Mg can improve the homogeneity of eutectic silicon phase.The average length of eutectic silicon decreases from about 68 μm to about 61 μm when w(Mg) = 0.4%-0.71%.The microstructure uniformity of eutectic silicon phase is improved.The structure of silicon phase is conductive to free electron movement between primary α-Al and eutectic silicon,and the decrease of thermal conductivity tends to be gentle.Under the condition of fast cooling rate,all Mg enters Al matrix in the form of solid solution,which improves the strength of primary α-Al.

关 键 词：Al-9Si-xMg合金 组织 热传导性能 力学性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程]