Processing, microstructure and fracture behaviour of a spray-atomized and deposited nickel aluminide intermetallic

摘要

In this study, nickel aluminide intermetallics were synthesized using the spray atomization and deposition technique. Microstructure characterization studies were performed to provide an understanding of the intrinsic influence of spray processing parameters on the microstructure of the intermetallic. Numerical simulation was carried out to provide an understanding of the influence of deformation, heat transfer kinetics and thermal history of the droplets on the thermal profile, distribution and solidification. The microstructure of the intermetallic is discussed in the light of results obtained from experimental observations and numerical simulation. Ambient-temperature tensile tests reveal the intermetallics to have a high strength and acceptable ductility. The tensile fracture behaviour of the polycrystalline intermetallic is presented and discussed in the light of processing and thermal conditions during spray deposition and intrinsic microstructural effects. (C) 1998 Chapman & Hall. [References: 61]