POWDER PROCESSING OF INTERMETALLIC ALLOYS AND INTERMETALLIC MATRIX COMPOSITES

This presentation covers the use of powder metallurgy for the formation of monolithic intermetallics and intermetallic matrix composites. A notable development has been the fabrication of homogeneous high density compacts from elemental powders by reactive sintering. A variant process involving simultaneous pressurization in a hot isostatic press, termed reactive hot isostatic pressing, is applicable to those compounds that prove difficult to consolidate by pressureless reactive sintering. This paper describes the effects of various processing factors on fabrication of compounds including Ni3Al, NiAl, TaAl3, MoSi2 and their composites. A key concern is with processing effects on microstructure, selection of compatible ceramic reinforcing phases, and whisker alignment through injection molding.