强磁场对Sb-4.8％Mn合金初生相生长行为的影响  

EFFECT OF HIGH MAGNETIC FIELD ON THE GROWTH BEHAVIOR OF PRIMARY Sb PHASE IN Sb-4.8%Mn HYPOEUTECTIC ALLOY

作　　者：张超[1] 王强[1] 高翱[1] 刘铁[1] 娄长胜[1] 赫冀成[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：《金属学报》2008年第6期713-717,共5页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目50374027;教育部新世纪资助人才支持计划项目NCET-06-0289;111计划项目B07015资助

摘　　要：研究了均恒磁场及梯度磁场条件下Sb-4.8%Mn亚共晶合金凝固组织的变化.结果表明,在急冷条件下,初生Sb相呈小平面长大,棱角分明;在无磁场条件下重熔凝固时,初生Sb相的小平面特征消失,棱角消失,变为近球形,在均恒磁场条件下重熔凝固时,随着磁感应强度的增大,初生相呈现小平面趋势生长;但磁感应强度增大到某一值时这种特征随之消失,而且初生相的尺寸呈现先变大后变小的趋势,在梯度磁场条件下,磁感应强度(?)值以及|(?)d(?)/d(?)|都较小的情况下,正梯度对初生相有细化作用,负梯度使初生相粗化并呈现长条状,随着磁感应强度(?)值及|(?)d(?)/d(?)|的增大,上述现象变得不明显,强磁场可以使初生相的结晶温度提高,减小熔体的过冷度,降低凝固速率。The changes of solidified structure of Sb-4.8%Mn hypoeutectic alloy under uniform and gradient magnetic fields were examined. It was found that the morphology of primary Sb phase in the alloy changed from a faced to non-faceted one or from a non-faceted to faceted one, and the transition is dependent on cooling rate and magnetic flux density. The size of Sb particles increased at first and then decreased with the increase in magnetic flux density under uniform magnetic fields, furthermore, its size at a positive magnetic field gradient is smaller than one at a negative gradient when the product of the magnetic flux density and its gradient has a small absolute value. Thermal analyses indicated that the application of a high magnetic field increased the crystallized temperature of the primary Sb phase, decreased the undercooling of the melt and the solidification rate.

关 键 词：Sb-Mn合金 凝固组织 初生相 强磁场 对流 

分 类 号：TG111.4[金属学及工艺—物理冶金] TG115.21[金属学及工艺—金属学]