摘要
The semi-solid antiburning AZ61-1.0%Y magnesium alloy slurry with fine circular solid phase was fabricated by a novel type continuous mechanical stirring in this work.The microstructure of the semisolid slurry was characterized by a metallography microscope.The results show that the fine circular solid phase distributes uniformly in the slurry when the stirring temperature ranges from 600 to 605℃.With the increase of the stirring velocity,the size of the solid phase becomes smaller and smaller.With the increase of the stirring time,the size of solid phase gets finer,but if the stirring time is longer than the critical time,it will be coarsened abnormally.The mechanical properties of semi-solid AZ61-1.0%Y alloy are superior to those of the normally casting magnesium alloy.
The refining effect and mechanism of Sb on Mg2Si and the microstructure of the matrix were investigated.The results indicate that there are Mg3Sb2 particles in the composites with the addition of Sb,and Mg3Sb2 can promote the formation of fine polygonal type Mg2Si by providing nucleation site.Meanwhile,the grain size of Sb modified alloy is finer than that of the matrix. The improved microstructure results in the improvement of mechanical properties.The ultimate tensile strength is increased by 12.2%with the addition of 0.8%Sb.
基金
Project(50765005)supported by the National Natural Science Foundation of China
