电磁场作用下半固态ZL201合金显微组织特征

利用电磁场对合金熔体的搅拌或振荡作用,研究了交流电磁场作用下的ZL201铝合金半固态流变浆料组织·结果表明,交流电磁场对ZL201铝合金显微组织有显著的细化作用,在液相线温度(650℃)附近,电磁场作用下的流变浆料组织为细小的近球形晶粒,优于不加电磁场的浆料组织,适用于半固态成形·交流电磁场所引起的熔体强制对流,使处于强烈温度起伏条件下的初生枝晶二次臂机械断裂或根部熔断,这是结晶核心增加,组织细化的原因·

Microstructure of Semi-Solid ZL201 Alloy in Electromagnetic Field

Studies the microstructure of the semi-solid slurry of ZL201 alloy in AC electromagnetic field where a stirring or oscillating action is exerting on the alloy melt. The results show that the AC electromagnetic field has an obvious refining effect on the microstructure of the alloy slurry, i.e. the fine near-spherical crystal grains take place in the vicinity of liquidus temperature or 650°C. Such a microstructure is superior to that not put in electromagnetic field and suitable for semi-solid forming. The convection in metal as forced by the electromagnetic field will cause the secondary branches of the primary dendrites to break off or burn out at root when the temperature is fluctuating violently, which is just the key reason why the number of crystal nuclei increases in the slurry and the microstructure becomes finer and more uniform.