Improving the dry sliding-wear resistance of B4C ceramics by transient liquid-phase sintering

Abstract

A critical comparison is made between the dry sliding-wear resistance of a B4C composite fabricated by transient liquid-phase sintering with Ti-Al intermetallic additive and two reference monolithic B4C ceramics fabricated by solid-state sintering. It is shown that, as a consequence of its full densification and super-hardness, the B4C composite is, despite containing secondary phases, markedly more wear resistant (significantly lower coefficient of friction, specific wear rate, worn volume, and wear damage) than the reference monolithic B4C ceramic fabricated under identical spark-plasma-sintering (SPS) conditions, and at least as wear resistant as the reference monolithic B4C ceramic fabricated at much higher SPS temperature. In all materials, wear is nonetheless mild and occurred by two-body abrasion dominated by plastic deformation at the micro-contact level plus, in the porous reference monolithic B4C ceramic, three-body abrasion dominated by fracture. Implications for the lower-cost manufacture of superhard B4C tribocomponents are discussed.