Analysis of on-deposition solidification during the Osprey spray-deposition process

The on-deposition process during spray deposition was studied. The theory of forced convection in the case of laminar flow is applied to evaluate the heat-transfer coefficient between the atomizing gas and the semi-solid/semi-liquid thin film on the surface of the deposit. The cooling rate of the on-deposition process was estimated, based on the heat-flow analysis. The results agree well with experimental observations of the microstructure of spray-deposited aluminium alloy, as well as other similar rapid solidification processes, such as gas atomization of metal powders.