摘要
以A356-1.3%Fe再生铝合金为原材料,通过Mg-Si熔体直接反应制备20%Mg2Si/A356-1.3%Fe铝基复合材料,研究B和Cr对复合材料组织中初始Mg2Si和富Fe相变质行为以及研究变质处理对拉伸性能和耐磨性的影响。结果表明:B和Cr分别对复合材料中的初生Mg2Si相和β-Fe相具有较佳的变质效果,B-Cr复合能够实现初生Mg2Si相和β-Fe相的同步变质。针状Fe相全部转变成汉字状或骨骼状α-Fe相,长径比减小近90%,初生Mg2Si相由粗大的树枝晶状转变成细小的颗粒状,平均尺寸由70.2μm减小到36.4μm,约下降50%。与A356-1.3%Fe再生铝相比,复合材料的耐磨性提高约3倍,而经B-Cr变质的复合材料其抗拉强度提高27%,断裂应变提高73%。
A356-1.3%Fe recycled aluminum alloy was chosen as raw material to prepare 20%Mg2Si/A356-1.3%Fe composites by direct melt reaction between Mg and Si.Modification behaviors of B and Cr elements on primary Mg_2Si and Fe-rich phases in the composites and its influence on tensile properties and wear resistance were mainly investigated.The results show that the elements of B and Cr can effectively modify primary Mg_2Si and Fe-rich phases,respectively.Simultaneous modification of primary Mg_2Si and Fe-rich phases can be effectively achieved by the combination of B and Cr.All of the needle-like β-Fe phases are changed into α-Fe phase like Chinese-script characters or skeleton.The aspect ratio of Fe-rich phase is reduced by 90%.Morphologies of primary Mg_2Si phase are changed from coarse dendrite to small granular.Its average size is reduced by about 50% from 70.2 μm to 36.4 μm.Compared with A356-1.3%Fe recycled aluminum,the wear resistance of the composites is improved by 3 times,and the tensile strength and elongation to failure of the composites modified by B and Cr are increased by 27% and 73%.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2017年第4期684-691,共8页
The Chinese Journal of Nonferrous Metals
基金
广东省省部产学研专项资金技术前沿项目(2013B090500091)~~
关键词
再生铝
复合材料
初生Mg2Si
富Fe相
变质
recycled aluminum alloy
composites
primary Mg_2Si phase
Fe-rich phase
modification
