Research on Laser Atomization Process for Preparation of Ultrafine Spherical AgCu Alloy Powder

AgCu alloy powder has both the advantages of Ag powder and Cu powder, and has broad application prospects in electronic manufacturing, catalysis and medical fields. Powder samples were prepared by pulse laser etching of AgCu eutectic alloy targets. The particle size, appearance, composition and microstructure of the powder samples were studied by scanning electron microscope, X-ray diffraction and differential thermal analysis. The results show that the particle size distribution of AgCu alloy powder is mainly in the range of 1 similar to 6 mu m. The powder particles are spherical and have a smooth surface. The average Ag content of the powder particles is close to that of the target, the composition is uniform on the most cross section. The microstructure of the powder is comprised of Ag-rich phase and Cu- rich phase. The onset melting temperatures of the powder and target are 773 and 779.5 degrees C, respectively; the melting temperature ranges of the two are similar, but the temperature range of the former is shifted to a lower temperature than the latter, which is presumed to result from the presence of metastable phase in the powder particles. The research results provide a feasible way for the preparation of high-performance ultrafine spherical AgCu alloy powders.