Ti对Al-Bi-Sn难混溶合金凝固组织的影响  

Effects of Ti Addition on the Solidification Microstructure of Al-Bi-Sn Immiscible Alloys

作　　者：杨永辉 张林[1] 张道琦 郭晓 王恩刚[1] Yang Yonghui;Zhang Lin;Zhang Daoqi;Guo Xiao;Wang Engang(Key Laboratory of Electromagnetic Processing of Material of Ministry of Education,Northeastern University;School of Metallurgy, Northeastern University)

机构地区：[1]东北大学材料电磁过程研究教育部重点实验室 [2]东北大学冶金学院

出　　处：《特种铸造及有色合金》2021年第11期1410-1415,共6页Special Casting & Nonferrous Alloys

基　　金：国家重点研发计划资助项目(2017YFE0107900);国家自然科学基金资助项目(51674083);国家111计划2.0资助项目(BP0719037)。

摘　　要：为解决Al-Bi-Sn难混溶合金易产生宏观偏析的问题,研究了添加Ti元素和提高冷速改善Al_(70)Bi_(15)Sn_(15)合金凝固组织的作用,分析了富Bi-Sn弥散相的形态、尺寸与宏观偏析。结果表明,随着凝固冷却速率提高,合金中的富Bi-Sn弥散相尺寸细化,宏观偏析减轻;添加Ti元素后,Al-Bi-Sn合金原位生成了棒状的硬质化合物Al_(3)Ti,在基体中交错分布,阻碍了Bi-Sn弥散相液滴的碰撞凝并,抑制其长大,液滴尺寸细化,且液滴形状由椭圆形转变为圆形。此外,Ti元素添加还降低了共晶组织凝固温度,同时弥散分布的硬质Al_(3)Ti金属化合物大幅提高了合金的硬度。To solve the macrosegregation of Al-Bi-Sn immiscible alloys,the effects of higher cooling rate and Ti addition on the microstructure of Al_(70)Bi_(15)Sn_(15) alloys were investigated,and the morphology,dimension as well as macrosegregation of Bi-Sn-rich dispersed phase were analyzed.The results indicate that the dimension of Bi-Sn-rich dispersed phase is refined and the macrosegregation is decreased with the increase of cooling rate.After Ti addition,the rod-shaped metallic compound of Al_(3)Ti is in-situ generated and presents staggered distribution,which retards the collision and inhibits the growth of Bi-Sn dispersed phase droplets.The droplets are refined,and transformed from elliptic shape to round shape.Moreover,Ti addition also reduces solidification temperature of Bi-Sn eutectic structure.Meanwhile,the hardness of Al-Bi-Sn alloy is improved substantially by the dispersed hard compound of Al_(3)Ti.

关 键 词：难混溶合金 Al-Bi-Sn 凝固组织 Ti元素 宏观偏析 

分 类 号：TG132.32[一般工业技术—材料科学与工程] TG146.23[金属学及工艺—合金]