FORMATION OF BORON-NITRIDE AND BORON-CARBIDE COMPOSITE BY NITROGEN IMPLANTATION AT ELEVATED-TEMPERATURE

Boron carbide (B4C) is a wear resistant material with hardness slightly less than that of diamond. It has an excellent strength to weight ratio and relatively high toughness under controlled processing. These essential mechanical properties make B4C an ideal candidate for cutting tool and bearing applications. We will demonstrate that hexagonal boron nitride (h-BN), a good solid lubricant, can be formed on B4C surfaces through high temperature (850-degrees-C) nitrogen ion implantation. The formation of composite B4C and h-BN on the B4C surface can potentially reduce surface friction coefficients, making the material more attractive for tribological applications.