DIAMOND DEPOSITION ON 3D TRANSITION-METALS AND THEIR ALLOYS

The characteristics of formation of diamond films using hot-filament c hemical vapor deposition on nickel and nickel-aluminum alloys have bee n investigated systematically. It has been found that the chemical nat ure of the substrate plays an important role in stabilization of graph ite (sp(2)-bonded) or diamond (sp(3)-bonded) phase. The transition met al substrates with a partially filled 3d shell, for example nickel, te nd to stabilize sp(2) bonding and catalyze the formation of graphite. By alloying the substrate with aluminum, it was possible to form diamo nd directly on the NiAl substrates. The mechanism of formation of diam ond on nickel-aluminum alloys, and the nucleation of diamond on single crystal graphite substrates are discussed. The importance of diamond coating on these technologically important structural alloys is descri bed briefly.