Mechanical characterizations of diamond carbon films made by PACVD

Mechanical and surface properties associated with their wettability were investigated for diamond films deposited on titanium alloy by a two-step microwave PACVD process at 600 °C. Polycrystalline and smooth fine grained diamond films were investigated. The elastic properties of the diamond layers were studied by Brillouin light scattering spectroscopy in order to determine their evolution as a function of the diamond purity. The effective elastic properties of these films with hexagonal effective symmetry were determined. The elastic constants decrease when diamond purity is lowered. The wettability tests can lead to the determination of superficial energy. A strong correlation is noticed between the wettability and superficial energy with the content of sp2.