强磁场对Al-7%Si合金凝固过程中初生α-Al枝晶分布的影响  

Effects of High Magnetic Fields on the Distribution of Primaryα-Al Dendrites of Al-7%Si Alloys During Solidification

作　　者：王长久[1] 董蒙[1] 刘铁[1] 高鹏飞[1] 牛书秀 苑轶[1] 

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,沈阳110004

出　　处：《材料导报》2016年第2期90-94,共5页Materials Reports

基　　金：国家自然科学基金(51271056);中央高校基本科研业务费项目(N130302005)

摘　　要：采用超导强磁场装置研究了磁场强度对有、无细化剂颗粒Al-7%Si(质量分数)合金凝固组织的作用效果。研究发现,施加强磁场使无细化剂颗粒合金中的初生α-Al枝晶转变为发达枝晶形貌,二次枝晶生长充分,三次枝晶分支明显,枝晶尖端清晰可见;晶粒细化,且枝晶主轴与磁场方向呈30°规则排列。施加强磁场后初生α-Al枝晶数量和Si在α-Al中的溶解度都有少量增加。强磁场抑制添加细化剂合金熔体中的对流,加剧了Ti的重力偏析,使初生α-Al相出现明显枝晶化趋势,方向性增强,枝晶臂粗化明显。The effects of high magnetic fields on the solidification behavior of refined and non-refined Al-7wt% Si alloys with superconducting magnetic fields device were investigated. The results indicate that the α-Al dendrites transform into developed dendrites, secondary dendrites arms grow fully, teriary dendritic branches are obvious by imposing high magnetic fields; grains are refining and the dendrites principal axis with the magnetic fields direction angle at a 30 degrees. The number of α-Al dendrites and the solubility of Si in α-Al dendrites obtained a small increase by imposing high magnetic fields. Strong magnetic fields suppress the refined alloy melt convection, intensify Ti gravity segregation, and the α-Al of specimens refined appears obviously dendritic trend by imposing high magnetic fields, and shows a strong directional, dendrite arms coarsening obviously.

关 键 词：强磁场Al si合金凝固枝晶 

分 类 号：TG14[一般工业技术—材料科学与工程]