Thickness study of vanadium carbide interface for deposition of DLC films

Resumo

The method PECVD (Plasma Enhanced Chemical Vapor Deposition) enables the growth of hard DLC films, wear-resistant antifriction, with over bonds sp3 and less bonds hydrogen. This paper presents an experimental evaluation process of formation of vanadium carbide layer (VC) by reactive thermodiffusion process for subsequent deposition of DLC. The salt bath is carried out by mixing the reagents: sodium tetraborate decahydrate, vanadium pentoxide and boron carbide. A conical crucible with lid was used, with capacity of 25 grams. The method PECVD used: 200torr vacuum, argon at 1,5sccm, -600V at 0,05torr for 20 minutes, and acetylene at 1sccm, -750V for 40 minutes at 0,07torr and 180°C. It were used the tool steels AISI H13, D2 and O1. The layers of VC were characterized by SEM-EDX/EDS and XRD, and the DLC films were characterized by SEM-EDS, Indentation Test and Raman Spectroscopy. The oxygen proved to be harmful to growth in VC steel substrates by reactive thermodiffusion process. The project of conical crucible with lid reached the goal and contributed to the stabilization of thermodiffusion process, restricting efficiently oxygen environment ensuring complete immersion of the sample, and allowing the growth of VC uniform, homogeneous and efficient for subsequent deposition of DLC films.