挤压铸造工艺对Al-7Si-0.4Mg-0.3Er汽车左支架组织与性能的影响  

Effect of Squeeze Casting Process on the Microstructure and Properties of Al-7Si-0.4Mg-0.3Er Alloy for Automotive Engine Left Bracket

作　　者：亓鹏 李伯龙[2] 王同波[2] 周廉 聂祚仁[2] Qi Peng;Li Bolong;Wang Tongbo;Zhou Lian;Nie Zuoren(Beijing University of Technology,Beijing 100124,China;Northwest Institute for Nonferrous Metal Research,Xi'an 710016,China)

机构地区：[1]北京工业大学材料科学与工程学院,北京100124 [2]北京工业大学,北京100124 [3]西北有色金属研究院,陕西西安710016

出　　处：《稀有金属材料与工程》2020年第4期1360-1365,共6页Rare Metal Materials and Engineering

基　　金：国家自然科学基金创新研究群体项目(51621003);科技创新服务能力建设-科研基地-北京实验室-现代交通金属材料与加工技术北京实验室(参与)(市级)。

摘　　要：利用OM、SEM微观组织分析以及显微硬度测试研究了挤压铸造成形工艺对Al-7Si-0.4Mg-0.3Er铝合金汽车发动机左支架显微组织和性能的影响。结果表明:凝固顺序对铸件不同部位微观组织影响较大,较先凝固左支架薄壁区初生α-Al组织相较于后凝固厚壁区细小。低温浇注成形相较于高温浇注制备左支架初生α-Al更为细小且均匀分布,但低温浇注支架晶间Er-π-AlFeMgSi相粗大且偏聚分布。高挤压速度相较于低速制备左支架晶间Er-π-AlFeMgSi相更为均匀细小。低温650℃高速成形铸件热处理后显微硬度(HV)为1190 MPa,标准偏差为50 MPa,相较于低温低速制备左支架(140 MPa)性能分布均匀。铝合金发动机支架适于在低温浇铸高速挤压铸造成形。The effect of squeeze casting process on the microstructure and properties of Al-7Si-0.4 Mg-0.3Er alloy bracket was investigated by OM,SEM and microhardness test.The results show that the solidification sequence has great influence on the microstructure of different parts of the bracket.The size of primaryα-Al grains in the first solidified thin-wall is smaller than that in the later solidified thick-wall.The primaryα-Al phase in the bracket fabricated by low pouring temperature is smaller and more uniformly distributed than that fabricated by high pouring temperature,but the Er-π-AlFeMgSi phase in the bracket fabricated by low pouring temperature is coarse and partially distributed.The Er-π-AlFeMgSi phase in the bracket fabricated by high speed is smaller and more uniformly distributed than that fabricated by low speed.The microhardness(HV)and standard deviation of the bracket fabricated by low pouring temperature(650℃)and high speed are 1190 and 50 MPa after heat treatment,respectively.The properties are more uniformly distributed than those of the bracket fabricated by low temperature and low speed.Al-Si alloy engine bracket is suitable for forming at low pouring temperature and high extrusion speed.

关 键 词：挤压铸造 Al-7Si-0.4Mg-0.3Er 汽车发动机左支架 浇注温度 挤压速度 

分 类 号：TG146.21[一般工业技术—材料科学与工程]