Preparation of tin alloys spherical fine metal powders by centrifugal atomization based on mono-sized droplets

Abstract

A novel hybrid method for the production of spherical fine metal powders by centrifugal atomization based on mono-sized droplets was proposed. In this method, the mono-sized droplets were prepared by pulsated orifice ejected system, and then the droplets were atomized by centrifugal atomization. The powders with smooth surface, small particle size, narrow particle size distribution, high spherical degree and no satellite powders were prepared by this method. Fine Sn63Pb37, Sn0.3AgCu powders were prepared by this method. The effects of heated treatment on rotation disk and different disk materials Cu, Ni, 304 stainless steel on the preparation of the powders were studied, the difference between the experimental value and the theoretical value of particle size was analyzed, and the disintegration mode of liquid film in atomization process was discussed. The results show that the liquid film on the rotation disk tends to be thin and the average particle size of powders can be refined by heating the rotation disk. The better the wettability between the rotation disk and the metal material, the smaller the average particle size of the powders obtained, and the theoretical value of powders is higher than the experimental value, the smallest average particle size of the powders is 21.0 μm prepared by copper rotation disk. The mode of liquid disintegration in this method is related to the wettability between the rotation disk and the metal material, the copper rotation disk shows direct droplets disintegration, the nickel rotation disk shows film disintegration, the 304 steel rotation disk does not show liquid disintegration.

Keywords

• mono-sized droplets centrifugal atomization method
• spherical fine metal powder
• rotation disk material
• liquid disintegration