机械合金化制备纳米晶Fe-Si合金的研究

采用Fe-6．5％Si合金粉与Si-22％Fe合金粉末，经机械合金化制备了Fe-13．95％Si固溶体合金。由碰撞频率、速率与球磨工艺条件的理论关系推导出了球料比的最佳值。利用XRD、SEM和EDX手段对球磨后的Fe—Si粉体进行了结构、形貌及成份表征。结果表明：混合粉体球磨12h可实现机械合金化，合金化的粉体为α—Fe（Si）过饱和固溶体，颗粒尺寸为0．5～15μm，显微组织为纳米晶结构，平均晶粒尺寸约为18nm。

Study on nanocrystalline Fe-Si alloy synthesized by mechanical alloying

Fe-13.95wt% Si solid solution alloys have been prepared by mechanical alloying with mixed powders of Fe-6.5wt % Si alloy powders and Si-22wt % Fe alloy powders. The optimum value of ball-to-powder weight ratio has been deduced from theoretical relationship between frequency, speed of collision and ball-milling conditions. Structure, shape and composition of the milled Fe-Si alloy powders have been characterized by XRD, SEM and EDX. The results show that mechanical alloying can be realized by ball milling the mixture for 12h and the mechanically alloyed powder is Fe-Si supersaturated solid solution. The final powders mainly consist of some particles with a grain size from several microns to over ten microns, while these particles are composed of some subgrains with a nanocrystalline size of about 18 nanometers.