Adherence measurements of nanodiamond thin films grown on Ti6Al4V alloy

Nanodiamond thin films with high-density nucleation were successfully deposited on Ti6Al4V alloy by using an enhanced 2.45 GHz microwave assisted technique, based on discharge surface-wave guide (Surfatron system). A negative bias voltage of -400 V was applied between the plasma shell and substrate using 8% methane in hydrogen during the nucleation step. These films showed a good quality and a total residual stress, that depends on the technique used for substrate preparation, from -1.4 to -2.8 GPa that were evaluated by Raman scattering spectroscopy. Diamond films adherence on Ti6Al4V alloy was investigated as a function of substrate preparation and film growth time. A Rockwell indenter with loads higher than 1471 N was used for this test and the films deposited on substrate jetted with glass micro-spheres presented the best adhesion. This adherence was analyzed from the films images after the indentation test by Scanning Electron Microscopy (SEM).