Interfacial Properties Between CVD Diamond and Titanium

Abstract

The role of carbide and oxy-carbide films in the adhesion of diamond films on commercial pure Ti metal, and a Ti, 6%Al, 4%V substrates was examined. It was found that the carbon to oxygen ratio in an oxy-carbide structure formed at the interface broadly correlates with the adhesive strength of the diamond/substrate bond. Deposition experiments with substrates including titanium and its alloys, suggest the nature of the substrate is important in aiding carbide and subsequently, diamond formation. XPS depth profiling for Ti-6Al-4V indicates that the mode of TiC formation on pure Ti and Ti-6Al-4V is significantly different because of the segregation of aluminium. This contributes to a change of TiC stoichiometry and morphology. SIMS depth profiles also show that the interfacial surface on Ti-6Al-4V contains several percent of aluminium and nitrogen, both at the outermost surface and in the interior of the interfacial layer. The aluminium is enriched at the surface as compared with the bulk concentration.

Nanostructured diamond coatings for orthopaedic applications

“…CVD diamond on titanium and the biomedical alloy Ti-6Al-4V has been explored by numerous researchers (Scardi et al , 1997, Perry, 1993, Ager and Drory, 1993, Askari et al , 2008, Azevedo et al , 2005, Baek et al , 2003, Buccioni et al , 1999, Fu et al , 2003, Terranova, 1996). Issues deemed to be particularly important in this system include the potential hydrogen embrittlement of titanium, the large thermally induced residual stress in the diamond coating, relative amounts of interfacial titanium carbide, titanium hydride, and titanium oxide phases, and plastic flow of the substrate.…”