POWDER METALLURGY, cilt.42, sa.2, ss.157-163, 1999 (SCI-Expanded)
A gas atomisation unit was designed and constructed using free fall liquid metal delivery and a Mannesmann type nozzle. Nozzle geometry, liquid metal flowrate, gas type, and pressure were varied and the effects of these variables on powder mean size, powder morphology, and cooling rate were investigated. Powders with mean size d(50) as low as 20 mu m were obtained. Powders with mean size d(50) greater than 20 mu m had irregular shapes and cellular-dendritic structures; smaller powders had spherical shapes and smooth surfaces.