Sr变质对铸造Al-Si-Mg合金组织与性能的影响

Effects of Sr-Modification on Microstructure and Properties of As-cast Al-Si-Mg Alloy

采用扫描电镜、拉伸试验机和激光导热仪,研究了Sr变质处理对Al-3.2Si-0.8Mg合金显微组织、铸造流动性、力学性能与导热系数的影响。结果表明,随着Al-10Sr合金添加量的增加,共晶Si逐渐细化,Al-3.2Si-0.8Mg合金的铸造流动性、抗拉强度、伸长率和导热系数逐渐提高。当Al-10Sr合金添加量为0.4%时,Al-3.2Si-0.8Mg合金的铸造流动性试样长度为922mm,抗拉强度和伸长率分别为243MPa和11.3%,导热系数为187.6W/(m·k),与未变质处理相比,Al-3.2Si-0.8Mg合金的铸造流动性提高了8.2%,抗拉强度和伸长率分别提高了3.8%和11.9%,导热系数提高了3.1%。

The effects of Sr - modification on microstructure, casting fluidity, thermal conductivity and mechanical properties of as-cast Al-3.2Si -0.8Mg alloy are researched by scanning electron microscope, tensile testing machine and flash thermal conductivity meter. The results show that the casting fluidity, tensile strength, elongation and thermal conductivity are improved gradually as the increase of Al - 10Sr alloy addition. When the addition of Al - 10Sr alloy is 0 .4% , the length of casting fluidity sample is 922mm, the tensile strength and elongation are 243MPa and 11. 3%, and the thermal conductivity is 187.6W/（m·k） . Compared with non - modification, the casting fluidity of Al -3.2Si -0. 8Mg alloy is increased by 8.2%, tensile strength and elongation is improved by 3. 8% and 11. 9%, the thermal conductivity is increased by 3.1%.