Materials Science Forum, Vol.299, 392-397, 1999
Microstructure-property studies in spray formed Al alloys
A spray formed and forged Al-5Cr-1.5Zr (wt%) alloy was studied. The microstructure and tensile properties were evaluated, before and after forging, and compared to alloys of similar composition processed by a RS/PM route. The microstructure of the spray formed material consisted of clusters of Al13Cr2 intermetallics evenly distributed throughout the matrix, The coarse microstructure in the spray formed alloy was attributed to the cooling rates experienced during spray forming which are lower than the cooling rates experienced by the powder particles in gas atomisation The grain size of the spray formed alloy was an order of magnitude larger than the atomised and extruded alloy. The supersaturation of the alpha-Al matrix of the spray formed material in Zr was at a lower level compared to the RS/PM alloy. This resulted in poor ageing response and lower tensile properties.
Keywords:ALUMINUM-ALLOYS;POWDERS