电磁搅拌下半固态AZ91D镁合金的组织形成  

Microstructural Formation of Semi-solid AZ91D Mg Alloy Stirred by Electromagnetic Field

作　　者：毛卫民[1] 李强[1] 甄子胜[1] 陈洪涛[1] 钟雪友[1] 

机构地区：[1]北京科技大学

出　　处：《特种铸造及有色合金》2005年第3期161-163,共3页Special Casting & Nonferrous Alloys

基　　金：国家重大基础研究规划项目(G2 0 0 0 0 672 0 2 ) ;国家 863计划资助项目(G2 0 0 2AA3360 80 ) ;国家自然科学基金资助项目(50 3740 1 2 )

摘　　要：利用电磁搅拌装置、合金熔体淬火方法和EBSD位相显微分析技术 ,在不同的搅拌功率下 ,研究了电磁搅拌对半固态AZ91D镁合金微观组织的作用。结果表明 ,在电磁搅拌条件下凝固 ,AZ91D镁合金组织中的初生α Mg得到明显细化 ,初生α Mg转变为细小的蔷薇状或球状 ,EBSD检测表明这些球状初生α Mg晶粒在空间上大多属于不同的晶粒 ;电磁搅拌功率是重要的制备参数 ,搅拌功率越大 ,半固态AZ91D镁合金组织中的蔷薇状初生α Mg越少 ,而球状初生α Mg越多 ,晶粒也越细小 ;在电磁搅拌条件下 ,AZ91D镁合金熔体的激烈流动导致了较为均匀的温度场和溶质场 ,也导致了更加剧烈的温度起伏 ,这些现象导致了半固态AZ91D镁合金组织的形成。With the help of an electromagnetic stirring device,alloy melt quenching and EBSD analysis technology,the microstructure of semi-solid AZ91D magnesium alloy stirred by rotative electromagnetic field with various stirring powers was observed.The results showed that primary α-Mg phase in solidification structure of electromagnetic field stirred AZ91D Mg alloy can be obviously refined to fine rosette-like or spheroidal grains,which are proved to be different grains in three-dimension by EBSD analysis.It was found that the higher the stirring power the finer the primary α-Mg phase,and the less the number of the rosette-like grains,and the more the spheroidal grains.The theoretical analysis indicated that the vigorous flow motion of AZ91D Mg alloy melt ensure more uniformly temperature and solute field as well as larger temperature fluctuation resulting in the formation of the microstructure of semi-solid Mg alloy.

关 键 词：AZ91D镁合金 电磁搅拌 显微组织 半固态 

分 类 号：TG249[金属学及工艺—铸造]