摘要
采用等温-双向电磁搅拌方法处理了A356合金熔体,研究双向电磁搅拌不同作用时间对浆料组织及结晶方式的影响。结果表明：在搅拌温度595℃、搅拌功率1200 W、搅拌时间5-15 min下等温-双向电磁搅拌能制备出具有近球状初生相的A356合金半固态浆料,初生相经历长大、分离、再长大的过程,短时或长时搅拌得到的初生相粗大、分布不均匀,在合适的时间内才能制备出理想的半固态浆料。长时间的等温-双向电磁搅拌影响共晶组织的形成平衡条件,发生离异共晶,在凝固组织中出现球状或近球状初生硅。等温-双向电磁搅拌处理合金熔体产生的近球状组织是枝晶臂断裂机制和晶粒抑制生长机制共同作用的结果。
A356 alloy melt was processed by isothermal-reversible electromagnetic stirring method, and the effects of isothermal-reversible electromagnetic stirring in different time on slurry microstructure and crystallization mode were investigated. The results show that A356 aluminum alloy semi-solid slurry with near-spheric primary phase can be prepared by using isothermal-reversible electromagnetic stirring at stirring temperature 595 ℃, stirring power 1.2 k W, and stirring time10-15 min. The primary phase experiences the process of grain growth, separation, and grain coarsening. The primary phase obtained by short or long time stirring is coarse,and distribution is nonuniform. The ideal semi-solid slurry only can be prepared at the appropriate time. The isothermal- reversible electromagnetic stirring for long time affects the equilibrium conditions of eutectic formation, and produces divorced eutectic. Spherical or near spherical primary silicon appears in the solidification microstructure. The nearly spherical microstructure of the alloy melt produced by isothermal- reversible electromagnetic stirring is the results of common action of dendrite arm fracture mechanism and inhibit the grain growth mechanism.
出处
《热加工工艺》
CSCD
北大核心
2016年第5期48-51,共4页
Hot Working Technology
基金
辽宁省高等学校优秀人才支持计划项目(LJQ2014064)
辽宁工业大学教师科研启动基金项目(X201309)
关键词
A356铝合金
双向电磁搅拌
初生相
共晶组织
A356 aluminum alloy
reversible electromagnetic stirring
primary phase
eutectic microstructure
