Li含量对Al-Si-Mg-Li合金组织与性能的影响  

Effect of Lithium Content on Microstructure and Properties of Al-Si-Mg-Li Alloys

作　　者：乔振[1] 赵中魁[1] 孙清洲[1] 张普庆[1] 王桂青[1] 

机构地区：[1]山东建筑大学材料科学与工程学院,山东济南250101

出　　处：《铸造技术》2010年第8期1040-1043,共4页Foundry Technology

基　　金：山东省优秀中青年科学家基金项目(2006BSB01417);山东省自然科学基金项目(Y2007F39)

摘　　要：研究了不同含Li量对Al-7Si-0.5Mg合金显微组织和性能的影响,合金采用真空电阻炉熔炼,利用金相显微镜观察合金组织,采用DSC分析析出相,用维氏硬度计测定硬度。结果表明,Li使含7%Si的Al-Si-Mg-Li中出现初晶硅,随着Li含量的增加,初晶硅数量增多,尺寸变大,形状也由卵状逐渐变为三角状。Li抑制合金中沉淀相的析出,使时效强化效果变差。加入Li后,合金的伸长率,随含Li量增加,伸长率下降;抗拉强度提高,在含2%Li时达到245 MPa。The effect of Li content on microstructure and property of the Al-7Si-0.5Mg alloys were investigated. Alloys were melted in a vacuum resistant furnace. Microstructure was observed by optical microscopy, DSC was employed to determine the phase precipitation by differential scanning calorimeter, and hardness was measured by Vicker＇s hardness tester. The results show that primary Si phase appeared in the microstructure of Al-Si-Mg-Li containing 7 % Si. Primary Si phase changed from oval to triangle shaped and its amount and size increased with the increment of Li. Precipitation phases were inhibited that made the alloys being hardened poorly by ageing. With the Li addition the alloys were lower in elongation and higher in strength, and the elongation decreased with increase of Li content. The alloys containing 2% Li has the maximum strength of 245 MPa.

关 键 词：LI AL-SI-MG合金 组织 性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]