Si含量对Al-Si-Mg合金铸造流动性、热导率和力学性能的影响  

Effects of Si Content on Casting Fluidity, Thermal Conductivity and Mechanical Properties of Al-Mg-Si Alloy

作　　者：牛艳萍 赵禹凯 王顺成 郑开宏 

机构地区：[1]广东省工业分析检测中心,广东广州510651 [2]广东省材料与加工研究所,广东广州510651

出　　处：《铸造》2016年第4期366-370,共5页Foundry

基　　金：广东省科技厅科技计划项目(2015B090926013;2014B070706027;2013A090100002);广州市科技计划项目(2014Y2-00214)

摘　　要：采用金相显微镜、激光导热仪、拉伸试验机和扫描电镜,研究了Si含量对Al-Si-Mg合金铸造流动性、热导率和力学性能的影响。结果表明:随着Si含量的提高,由于共晶液相的增加和α-Al枝晶的细化,使Al-Si-Mg合金的铸造流动性获得提高,而晶界上共晶Si和Mg2Si相数量的增加,又使Al-Si-Mg合金的抗拉强度得到提高,但伸长率和热导率有所下降。当Si含量为3.23%时,Al-Si-Mg合金的铸造流动性试样长度为784 mm,热导率为186.3 W/m·k,抗拉强度和伸长率分别为236 MPa和9.2%。The effects of Si content on casting fluidity, thermal conductivity and mechanical properties of Al-Mg-Si alloy were investigated by metallurgical microscope, flash thermal conductivity meter, tensile testing machine and scanning electron microscope. The results show that with the increasing of Si content, the casting fluidity of Al-Si-Mg alloy are improved due to the increase of the number of eutectic liquid phase and the refinement of the α-Al dendrite grain. The tensile strength of Al-Si-Mg alloy is improved, the elongation and the thermal conductivity are decreased due to the increment of the amount of eutectic Si and Mg2 Si phases in α-Al grain boundaries. When the Si content is 3.23%, the length of casting fluidity sample of Al-Si-Mg alloy is 784 mm, the thermal conductivity is 186.3 W/m·K, the tensile strength and elongation are 236 MPa and 9.2%,respectively.

关 键 词：AL-SI-MG合金 铸造流动性 热导率 抗拉强度 

分 类 号：TG146.21[一般工业技术—材料科学与工程]