機械的 合金化 方法에 의한 Fe-Si 合金製造에 關한 硏究

A study on the synthesis of Fe-Si alloy by mechanical alloying

The microstructural evolution during mechanical alloying of elemental Fe and Si powders, average composition Fe₃₀Si₇₀ and Fe₅₀Si₅₀, has been investigated by X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Differential scanning calorimetry (DSC). Mechanical alloying was performed by using a SPEX 8000 Mixer/Mill under argon atmosphere with/without hexane as a process control agent (PCA). In the presence of PCA, the milling process was dominated by fracture resulting in the decrease in particle size to about 1㎛. The structural development with milling time depended on the average composition of starting powders. The mixture of Fe₅₀Si₅₀ and Fe₃₀Si₇₀ resulted in the formation of FeSi(ε-phase) and FeSi₂(β-phase), respectively. In the case of Fe₃₃.₃Si₆₆.₇ a mixture and FeSi₂(β)was formed. These results were discussed by considering the thermodynamics and kinetics concerning the milling process.