电磁搅拌工艺参数对半固态AZ91D镁合金组织的影响  

Effect of Electro-magnetic Stirring Process Parameters on the Microstructure of Semi-solid AZ91D Alloy

作　　者：甄子胜[1] 毛卫民[1] 陈洪涛[1] 钟雪友[1] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083

出　　处：《北京科技大学学报》2003年第4期341-345,共5页Journal of University of Science and Technology Beijing

基　　金：国家重点基础研究"973"发展规划资助项目(No.G200067202-3)

摘　　要：研究了电磁搅拌工艺参数对半固态AZ91D合金组织的影响规律.结果表明:电磁搅拌条件下半固态AZ91D合金组织的固相颗粒为蔷薇状或粒状α-Mg,随电磁搅拌功率的增大,蔷薇状形态逐渐消失,固相颗粒形态趋于粒状和圆整;在实验范围内,随电磁搅拌电源频率的增大,半固态AZ91D合金组织中固相颗粒形态越来越圆整.这主要是由于电磁搅拌条件下半固态AZ91D合金组织的形成机理是以枝晶臂熔断为主,而在高频率下的电磁搅拌过程中,在搅拌室产生的集肤效应使得表面和中心出现宏观温度差,从而加强了固相颗粒随流场运动时的温度起伏,最终加速了枝晶的熔断.The effect of electro-magnetic stirring process parameters on the microstructure of semi-solid AZ91D alloy was studied. The results showed that the shape of solid particles in the alloy was rosette-like or granular. With the stirring power increasing, the rosette-like particles disappeared gradually, and solid particles got more and more spherical. A higher power made the solid particles of the alloy more spherical, because the main evolution mechanism of microstructure of the alloy was the dendritic arm melting method. A higher frequency introduced a skin effect on the stirred semi-solid slurry, which made a temperature difference between the edge and the center. The slurry under electro-magnetic stirring took a secondary flow besides the horizontal rotating flow, which made the slurry move from the edge to the center in cycles. This secondary flow resulted in a promotion of dendritic arm being melted away from the dendrite grains by the large temperature fluctuation.

关 键 词：镁合金 半固态AZ91D合金 显微组织 电磁搅拌 工艺参数 搅拌功率 集肤效应 

分 类 号：TG146.22[一般工业技术—材料科学与工程] TG113.12[金属学及工艺—金属材料]