【摘要】 利用超音速气雾化的方法制备了液态微溶、固态不互溶的Ag5Fe粉末。利用电弧在放电时的高温使Fe熔解于Ag中,在随后的快速凝固过程中形成含有亚稳合金相的Ag5Fe粉末。扫描电镜观察显示:Ag5Fe粉末的粒度较均匀、细小,呈正态分布,大部分集中在25～55μm;取典型颗粒放大处理后发现:颗粒的富Ag基体中高度弥散分布着粒度在纳米级的Fe相,在富Fe基体中亦有粒度为纳米级的弥散分布的Ag相。计算结果表明:经超音速气雾化之后Ag-Fe合金颗粒有固溶,且粉末颗粒越细小固溶扩展越大。Fe在富银区域中的固溶度亚稳扩展至0.3at%～0.6at%;且在忽略少数粒度较大的粉末颗粒条件下,粉末颗粒越细,亚稳固溶度越大。更多还原

【Abstract】 The Ag5Fe powder,which is dissolved at liquid state a little but not dissolved each other at solid state,are produced in present work by a new technic,the ultrasonic arc gas atomization.Fe is dissolved in Ag matrix by using the high temperature produced by electric arc,to prepare the Ag5Fe powder with metastable alloy phase during later rapid solidification.It is testified by SEM that the Fe is forsooth dissolved in Ag matrix to form the mostly global,very uniform and thin Ag5Fe powers with particle size of about 25～55 μm.It is found from the typical particles selected that many Fe particles in nanometer are dispersing in Ag rich matrix even to about 0.3 at%～0.6 at% Fe by calculation,and many Ag particles in nanometer are dispersing in Fe rich matrix.Moreover the finer the particles are,the bigger the metastable solid solubility is,if ignoring few conditions of bigger powder particles.更多还原