Mao Weimin Li Qiang Zhen Zisheng Chen Hongtao Zhong Xueyou. Microstructural Formation of Semi-solid AZ91D Mg Alloy Stirred by Electromagnetic Field. [J]. Special Casting & Nonferrous Alloys (3):161-163(2005)DOI:
Microstructural Formation of Semi-solid AZ91D Mg Alloy Stirred by Electromagnetic Field
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。
Abstract
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.