Influence of Mn and Mg Contents on Mechanical Properties of the Die-casting Aluminum Alloy HL-111

In this study,four groups of thin plate samples with a wall thickness of 2.2mm,2.5mm,2.7mm,and 3.0mm are prepared by ultra-high vacuum die casting.The effects of Mn,Mg,and Mn/Mg ratio on the microstructure and mechanical properties of samples with different wall thicknesses are obtained by different test and analysis methods.The results show that as the content of Mn is 0.4%~0.65%,the content of Mg is 0.17%~0.5%,and the Mn/Mg ratio reaches 1.69~1.90,the tensile strength,yield strength,and elongation of HL-111 alloy with a wall thickness of 2~3mm can reach more than 280MPa,120MPa and 10%respectively,and the mechanical properties of the material are greatly improved.In addition,the tensile strength,yield strength,and elongation of HL-111 alloy after T5 heat treatment at 165℃for 510min reach 302.36 MPa,190.32 MPa,and 8.42%.The precipitated phase of Mg2Si leads to changes in strength and elongation.

免热处理高伸长率压铸HL-111铝合金的研究及应用

采用真空压铸制备了4组壁厚分别为2.2、2.5、2.7和3.0 mm的薄板试样,通过光谱分析、拉伸试验、金相组织分析、SEM断口形貌分析等方法,得出Mn、Mg元素含量及Mn、Mg质量比对不同壁厚试样微观组织及力学性能的影响。结果表明,当Mn含量为0.4%~0.65%、Mg含量为0.17%~0.5%,且Mn、Mg比达到1.69~1.90时,可以使壁厚为2~3 mm的HL-111合金抗拉强度、屈服强度和伸长率分别达到280 MPa、120 MPa和10%以上,力学性能显著提升。