摘要
采用铜模浇注法制备了厚度为3 mm的铝硅合金板材,研究了浇注温度与Sr元素对Al-7Si合金组织与性能的影响。结果表明,随着浇注温度由690℃升高至750℃,Al-7Si与Al-7Si-0.02Sr合金的平均晶粒尺寸均增大约10%,而Sr元素的添加对合金晶粒尺寸未见明显影响。浇注温度升高促使Al-7Si合金中共晶硅相尺寸增长,但对Al-7Si-0.02Sr合金中共晶硅相无明显作用;经Sr变质处理后,该合金中共晶硅相尺寸显著细化且分布更加均匀。浇注温度对两种合金的硬度几乎无影响,但Sr元素的引入使合金硬度由约60 HV提升至72 HV左右,规定非比例延伸强度由约75 MPa提升至90 MPa,断后伸长率由7.4%提高至9.4%。
Al-Si alloy sheets with a thickness of 3 mm were prepared using a copper mold casting method.The effects of pouring temperature and Sr addition on the microstructure and properties of Al-7Si alloy were investigated.Results show that increasing the pouring temperature from 690℃to 750℃increased the average grain size of both Al 7Si and Al-7Si-0.02Sr alloys by approximately 10%,while Sr addition had no significant effect on grain size.Elevated pouring temperatures promoted the growth of eutectic silicon phases in the Al-7Si alloy but had no noticeable impact on the Al-7Si-0.02Sr alloy.After Sr modification,the eutectic silicon phases were significantly refined and more uniformly distributed.Pouring temperature had little effect on the hardness of both alloys;however,the addition of Sr increased the hardness from approximately 60 HV to 72 HV,the non-proportional extension strength(Rp0.2)from 75 MPa to 90 MPa,and the elongation after fracture from 7.4%to 9.4%.
作者
吴青霖
WU Qinglin(College of Engineering,Hulunbuir University,Hulunbuir 021008,China)
出处
《铝加工》
2025年第6期23-27,共5页
Aluminium Fabrication
关键词
浇注温度
铝硅合金
变质
共晶硅
晶粒尺寸
pouring temperature
Al-Si alloy
modification
eutectic silicon
grain size
