Abstract
Spark erosion is a convenient,flexible,and low-cost method to quickly produce fine powders of met-als,alloys,and semiconductors in size ranging from nearly a hundred micrometers to submicrometer by repetitive spark discharges.Due to the complexity of the powder-forming journey,normally accompanied by high temperature,high pressure,decomposition,diffusion and rapid quenching caused by discharge plasma,the mechanisms of powder formation and possible contaminant infiltration are still controversial,posing a significant challenge to control particle size and chemical composition of the powder produced by this method.In this study,Fe-based amorphous powders in different particle-size distributions with high sphericity were fabricated by spark erosion under different discharge-energy conditions.The max-imum particle size of the resultant powders can be correlated with discharge parameters,crater depth,and crater radius,respectively.A multi-ring-breakup model is proposed to reveal the particle-size dis-tribution of the powder formed from the electrode melt under a single-pulse discharge.Furthermore,a dielectric-element infiltration model is provided to quantitatively evaluate the infiltration mass ratio of the contaminant elements,stemming from the decomposed products of dielectric liquid,in the resultant powder with different particle sizes.The models verified through the experimental data are significant for the development of high-performance fine Fe-based amorphous powder with controlled particle size and chemical composition.
基金项目
国家自然科学基金(52171150)
国家自然科学基金(51971006)
国家重点研发计划(2018YFA0703601)
中央高校基本科研业务费专项(YWF-22-L-513)
NETL
NSTL
万方数据