Synthesis and characterization of nano-crystalline CVD diamond film on pure titanium using Ar/CH_4/H_2 gas mixture

摘要

Titanium and Ti alloys have poor tribological properties and deposition of a well adherent diamond coating is a promising way to solve this problem. But diamond film deposition on pure titanium and Ti alloys is always difficult due to the high diffusion coefficient of carbon in Ti, the large mismatch in their thermal expansion coefficients, the complex nature of the interlayer formed during diamond deposition, and the difficulty of achieving very high nucleation density. A nano-crystalline diamond (NCD) film can resolve Ti and Ti alloys weak tribological performance due to its smooth surface. A well-adhered NCD film was successfully deposited on pure Ti substrate by using a microwave plasma assisted chemical vapor deposition (MWPCVD) system in the environment of Ar, CH_4 and H_2 gases at a moderate temperature. Detailed experimental results on the preparation, characterization and successful deposition of the NCD firm on pure Ti are discussed.