The Spray Forming of Nanostructured Aluminum Oxide

composites possess improved proper-ties such as tensile strength, fatigue strength, hardness, and wear resistance. Freestanding, near-net shape, nano-structured Al2O3 components can be synthesized via plasma-spray forming. In this study, plasma-spray parameters were optimized and an innovative sub-strate cooling technique was developed to retain nanosize Al2O3 in the spray deposit. Nanosize Al2O3 particles were partially melted and trapped between the fully melted coarser, micrometer-size Al2O3 grains. Densification of the spray-deposited Al2O3 occurred via solidification and sintering. A similar processing approach can be adopted for fabrication of near-net shapes of a variety of nanostructured materials (metals, ceramics, and intermetallics) and their combinations by selecting suitable powder-treatment and plasma-spray parameters