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Rapid solidification process was employed to make 6061 Al alloy powder. Powder size distribution was analyzed with SEM. Powder densities, i.e. apparent density and tap density, were measured. Thermal properties were measured via DSC. Surface condition and microstructures and their chemical compositions were characterized with XRD, OM, SEM/EDX. Nanoindentation was employed to obtain the hardness and Young’s modulus of the powders. The relationships among the atomization parameters, powder shapes and sizes, powder densities, thermal properties, microstructures and the mechanical properties were analyzed and rationalized.

A ~1.2 meter long trough comprising of variable cross-sections, with the highest ratio of depth to opening width reaching 1.4, is gas-formed at 500°C with superplastic aluminum alloy 5083. It is a challenge to successfully make such an industrial scale part as demonstrated in this paper. Starting as an expanded V-shaped groove, pressurized gas is manipulated to flow into the forming die, and the pressure vs. time profile needs to be calculated. Thus, the flow stress in the deforming material is optimal to maintain desired strain rate correspondingly. Thickness distribution over the formed product is far from uniform. The other even undesired result is that the thinnest region suffers severe cavitation