Wettability and corrosion tests of diamond films grown on Ti6Al4V alloy

Abstract

Diamond thin films were successfully deposited on both sides of jetted substrates Ti6Al4V alloy, without intermediate layers deposition, by using an enhanced 2.45 GHz microwave-assisted technique. This system is based on discharge surface-wave guide, Surfatron system. It was used as a bias-enhanced nucleation (BEN) applied between the plasma shell and the substrate, reaching a nucleation density around 5×10 9 parts cm −2 in just 5 min. These films showed a good quality and a total residual stress around −2.4 GPa that was evaluated by Raman scattering spectroscopy. In spite of the high residual stress, the films adhesion on substrate was excellent, even when a load of 250 kgf was applied. Wettability of these films designed a small hydrophobicity that is very similar to those of other carbon structures used as biological implants. The surface energy value of 50.5 mJ m −2 indicated that is possible to get a good tissue adhesion on diamond films. These films were also exposed to various biological fluids, including isotonic NaCl and Ringer's solution for 1 month and acid–water solution for 2 months. Diamond surface chemical stability was analyzed from films micrographs by scanning electron microscopy (SEM). The results revealed that the diamond films surfaces were not degraded by environmental agents.