Investigation of nozzle geometry on the particle size for powder production by gas atomisation

In this study, the effect of the nozzle geometry for powder production by gas atomisation was investigated. Powder production was carried out at the Dumlupınar Gas Atomisation unit. Different nozzle tip geometry and protrusion lengths were used for the investigation of particle size and powder morphology. Powder particle size was measured by using laser particle sizer, powder morphology was determined by using SEM. Nitrogen was used as the atomisation gas for the tin powder production. As the Gas/Metal mass flow ratio was increased the powder particle size was reduced. The higher protrusion length of the nozzle decreased the powder size. The smallest powder size of 12.05 microns was obtained with 10 mm protrusion length. The tip geometry at the same protruion length has no significant effect for the powder size. For the 5 mm protrusion length the two different tip geometry produced the powder size of 14,11 and 14,26 microns. Produced powders are mostly spherical and have smooth surfaces. A few satellite formation and cellular surface structure at the big powder surfaces were observed. Keywords: Gas Atomisation, , metal powder, nozzle geometry.