Mg和Si含量对一种低频电磁铸造新型高强Al-Mg-Si-Cu合金组织性能的影响  

Effect of Mg- and Si-content on Microstructure and Mechanical Properties of a New High Strength Al-Mg-Si-Cu Alloy Prepared by Low Frequency Electromagnetic Casting

作　　者：蒙毅 崔建忠[2] 赵志浩[2] 朱远志 

机构地区：[1]北方工业大学机械与材料工程学院,北京100144 [2]东北大学材料电磁过程研究教育部重点实验室,沈阳110819

出　　处：《材料研究学报》2017年第10期781-788,共8页Chinese Journal of Materials Research

基　　金：北京市优秀人才培养资助青年骨干个人项目(2015000020124G023);北方工业大学"优秀青年教师培养计划"(XN072-017);北方工业大学科研启动基金(1100000156041-2015)~~

摘　　要：结合金相组织观察及能谱分析、DSC热差分析、JMat Pro 5.0软件计算和室温力学性能测试,研究低频电磁铸造新型高强Al-Mg-Si-Cu合金铸态、挤压态和T6态的组织性能。结果表明,该新型合金系的均匀化温度和固溶温度可分别确定为540℃和550℃。Mg_2Si强化相能显著细化合金铸态组织且细化程度随其含量增大递增,而过量Si或过量Mg均能减弱细化剂和Mg_2Si相对合金铸态组织的细化作用。Mg的过量添加不会降低合金强度但可提高其延伸率至19%以上。该新型Al-Mg-Si-Cu合金中,当Mg质量分数为1.60%、Si质量分数为1.15%时,可获得较高强度(抗拉强度419 MPa、屈服强度362 MPa)而又不损害其塑性(延伸率18.75%)。The microstructure and mechanical properties of a new high strength Al-Mg-Si-Cu alloy prepared by low frequency electromagnetic casting（LFEC） alloy were studied by using optical microscope, energy dispersive spectroscopy（EDS）, DSC analysis, JMat Pro 5.0 software and mechanical tests at room temperature. The results show that the temperatures of homogenization and solid solution for the alloy can be identified as 540℃ and 550℃ respectively. Mg_2Si phase could refine the as-cast grain size obviously and its effect on the as-cast grain refinement increases with the increase of Mg_2Si content in the alloy. While, the refining effect of Mg_2Si and other grain refiners on the grain sizes of ingots will be reduced by the excess of Mg or Si. However, the excess of Mg content in the alloy increases the elongation to more than 19% without reducing its strength. With the addition of 1.60%（mass fraction）Mg and 1.15%（mass fraction） Si to the Al-Mg-Si-Cu alloy exihibits higher strength（ultimate tensile strength 419 MPa and yield strength 362 MPa respectively） with undiminished ductility（elongation 18.75%）.

关 键 词：金属材料 强韧性 高强铝合金 显微组织 

分 类 号：TG146.2[一般工业技术—材料科学与工程]