混合稀土变质对A390合金显微组织及力学性能的影响  

Study on the Microstructure and Mechanical Properties of A390 Aluminium Alloy Modified by Mixed Rare Earth

作　　者：王亚东 王建华 奎永才 雷强 吴华洋 李薇 隋育栋[3] WANG Yadong;WANG Jianhua;KUI Yongcai;LEI Qiang;WU Huayang;LI Wei;SUI Yudong(Yunnan Demeng Expressway Investment and Development Co.,Ltd.,Baoshan 678013,China;Yunnan Transportation Planning and Design Research Institute Co.,Ltd.,Kunming 650041,China;Faculty of Materials Science and Engineering,Kunming University of Science and Technology,Kunming 650500,China)

机构地区：[1]云南德孟高速公路投资开发有限公司,云南保山678013 [2]云南省交通规划设计研究院股份有限公司,云南昆明650041 [3]昆明理工大学材料科学与工程学院,云南昆明650500

出　　处：《铸造技术》2024年第5期487-493,共7页Foundry Technology

基　　金：云南省交通运输厅科技资助项目(云交科教便[2022]123号);云南交投科技创新计划项目(YCIC-YF-2022-20)。

摘　　要：铝硅合金拥有良好的成型性和较高的力学性能,被广泛应用于各个行业。但过共晶铝硅合金铸态组织中存在的粗大不规则块状初晶硅相会割裂基体,显著降低合金力学性能。本文采用OM、SEM及万能材料试验机等研究混合稀土La、Ce变质A390过共晶铝硅合金的微观组织和力学性能。结果表明,混合稀土对初晶硅的变质效果明显,随着混合稀土含量的增加,初晶硅的体积分数和合金的力学性能呈先增加后降低的趋势,当混合稀土加入量为0.58%(其中La为0.33%,Ce为0.25%,质量分数)时,初晶硅的体积分数达到最小值9.37%,铸态合金的抗拉强度和伸长率分别为229 MPa和1.7%。Aluminium-silicon alloys are widely used in various industries because of their good mechanical properties and high temperature resistance.However,the presence of coarse and irregular primary crystalline silicon phases in the original as-cast microstructure seriously affects the properties of per-eutectic aluminium-silicon alloys.In this paper,the effect of La and Ce on the microstructure and mechanical properties of A390 alloys was studied by OM,SEM and a universal material testing machine.The results show that mixed rare earth elements have an obvious metamorphic effect on primary silicon.With increasing amounts of mixed rare earth elements,the volume fraction of primary silicon and the mechanical properties of the alloy first increase and then decrease.When the amount of mixed rare earth is 0.58 wt.%(La is 0.33 wt.%,Ce is 0.25 wt.%),the volume fraction of primary silicon reaches the minimum value of 9.37%,and the tensile strength and elongation of the as-cast alloy are 229 MPa and 1.7%,respectively.

关 键 词：A390合金 混合稀土 初晶硅 共晶硅 力学性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程]