稀土对6063铝合金挤压性能的影响

Effects of Rare Earth on Microstructure and Properties of Squeezing Casting 6063 Aluminum Alloy

在6063铝合金中,添加不同量的稀土元素,并严格控制浇注、挤压工艺过程,对挤压试样进行拉伸试验及显微硬度测试,采用正交试验方法分析抗拉强度、伸长率和硬度相对较好的合金成分设计方案,并采用金相显微镜和扫描电镜观察合金的铸态组织结构,研究合金元素的影响。结果表明,Al-0.5Mg-0.38Si-0.2RE铝合金的挤压性能最好。添加稀土可以使铝合金的晶粒得到细化,并且可以有效地改善析出相的大小、形貌,6063D-RE合金的力学性能完全满足国家标准。

6063 aluminum alloy samples with varied RE additions were prepared by strictly controlling pouring process and squeezing casting parameters,and tensile testing and micro-hardness testing for the samples prepared were carried out.Optimized composition design was conducted by orthogonal method.In addition,microstructure of the as-cast alloy was observed by OM（optical microscope） and SEM（scanning electron microscope） to understand the role of RE in the alloy.The result shows that the Al-0.5Mg-0.38Si-0.2RE alloy exhibits desirable mechanical properties.Meanwhile,the grains size in the alloy can be refined,and size and morphology of precipitate can be improved effectively.The mechanical properties of 6063D-RE alloy can fully meet requirements of the national standard.