Method for manufacturing a reaction-sintered metal/ceramic composite

Abstract

A method is disclosed for manufacturing a reaction sintered composite article which comprises at least one ceramic component. The method comprises preparing a particulate mixture of precursor powders leading to the formation of said composite material upon reaction sintering, pressing said particulate mixture to a self-sustaining body, heating said body up to a temperature below the temperature at which the reaction sintering is initiated, comminuting the heat treating body, selecting particles of a suitable grain size distribution, pressing said particles into shapes of desired size and configuration, and heating said shapes up to a temperature at which the reaction sintering is initiated. The reaction sintered body comprises borides, carbides, nitrides or silicides of a transition metal of the groups IVb, Vb or VIb of the periodic table (comprising titanium, hafnium, zirconium, vanadium, niobium, tantalum, chromium, molybdenum and tungsten), and a metal oxide. In the case that the composite material comprises Al.sub.2 O.sub.3, TiB.sub.2 and facultatively Al, the precursor powder may comprise TiO.sub.2, B.sub.2 O.sub.3 and Al. Composite bodies of sizes, shapes, varying compositions or other particular configurations which do not allow for the preparation of the final bodies in one operation are produced by preparing sub-sections of precursor shapes which are pressed in a first pressing operation, assembled to a shape of essentially the final configuration, again pressed and reaction sintered.