多元稀土细化半固态A356铝合金初生α相的研究  

Research of multiple-element rare earth refining primary α phase in semi-solid A356 aluminum alloy

作　　者：刘政[1] 谌庆春[2] 许鹤君[2] 胡钱钱[2] 周翔宇[2] 

机构地区：[1]江西理工大学机电工程学院,江西赣州341000 [2]江西理工大学材料科学与工程学院,江西赣州341000

出　　处：《轻金属》2015年第1期49-53,共5页Light Metals

基　　金：国家自然科学基金项目(51361012);江西省自然科学基金项目(20114bab206014);科技落地计划(KJLD12070)资助

摘　　要：在A356铝合金中,同时添加稀土Ce、Y、Gd作为合金的细化剂,设计三因素三水平正交试验并结合电磁铸造技术,研究了多元稀土添加量对半固态A356铝合金初生α相的细化效果。试验采用近液相线(620℃)浇铸,并在电磁搅拌频率为30Hz时搅拌15s,搅拌完成后于590℃等温保温5min,淬火。以合金初生α相的形貌和尺寸为正交试验指标,研究了不同稀土对合金初生α相尺寸和形貌的影响,并得到最佳多元稀土添加的质量分数为:0.2%Ce+0.4%Y+0.4%Gd,此时,A356铝合金初生α相的平均等积圆直径为55.31μm,平均形状因子为0.83,其组织细小、均匀且圆整度高,可满足半固态流变成形的要求。The rare earth Ce, Y and Gd were selected as the refiner for semi - solid A356 aluminum alloy, meanwhile, the orthogonal experiment of three factors and three levels was designed to study the refining effect of multiple - element rare earth addition to primary α phase in semi - solid A356 alloy, combined with electromagnetic casting technology. The semi -solid A356 alloy was manufactured by low superheat pouring（620℃ ） and electromagnetic stirred under the condition of 30Hz and 15s, then isothermally held at 590℃ for 5 min after the stirring process completed, finally quenched. The morphology and grain size of primary ct phase were used as indicators of the orthogonal experiment to research the effect of different rare earth to primary ct phase of semi - solid A356 aluminum alloy. The best addition of multiple - element rare earth ：0.2% Ce ＋ 0.4% Y ＋ 0.4% Gd were gained, and the mi- crostructure of A356 aluminum alloy was smaller, more uniform and high rounded, and the average equal - area circle diameter of primary α phase was 55.311.Lm and the average shape factor was 0.83. Thus, this kind of semi - solid A356 aluminum alloy could meet the requirement of rheological forming.

关 键 词：A356铝合金 多元稀土 电磁搅拌 半固态 

分 类 号：TG146.21[一般工业技术—材料科学与工程]