Microstructural modifications induced by spray forming of Al–Cu alloys

Spray forming exhibited an equiaxed grain morphology of the primary α-phase in Al–4.5 Cu alloy, round to irregular non-dendritic morphology of the primary α-phase in Al–15 Cu alloy, particulate eutectic morphology in Al–33 Cu alloy and non-faceted growth morphology of the primary CuAl2 β-phase in Al–40 Cu alloy. Development of microstructure during spray forming of Al–Cu alloys is discussed in light of the solidification behaviour of droplets and spray-deposits.