【摘要】 采用超音速电弧喷射气雾化制粉设备制备了难固溶Ag-10Ni合金粉末。研究了粉末粒度分布、形貌及凝固组特征,并对雾化熔滴的冷却速率及过冷度、凝固组织的凝固次序、形成机制进行了分析。结果表明:粉末分散性好、粒度主要集中在20μm～45μm、平均粒度32μm、形貌主要为球形和近球形;粉末颗粒凝固组织为富Ag基体+弥散分布于基体中的细Ni相+位于芯部的大直径初晶富Ni相,在大直径初晶富Ni相中弥散分布析出Ag相;富Ag基体的凝固组织为树枝晶组织,小颗粒粉末(<20μm)枝晶间距小于0.2μm。更多还原

【Abstract】 The fine powder of Ag-10Ni immiscible alloy was prepared by Ultrasonic Arc Spray Gas Atomization process. The particle size distribution,morphology,microstructure evolution of the powder were studied in the present paper. It is shown that the particle size of the Ag-10Ni alloy powder ranges from 20 μm to 45 μm, the average particle size is about 32 μm, the powder possesses spherical form; the microstructure of the Ag-10Ni particle consists of the large spherical Ni-rich particles with dispersed Ag precipitates in the center part of the solidified droplets, Ag-rich matrix with dispersed tiny Ni-rich particles and Ni precipitates on outer part of large Ni-rich particles. The Ag-rich matrix has a dendritic structure. The interdendritic spacing is about 0.2 μm for the powder less than 20 μm.更多还原