Microhardness analysis of diamond like carbon films

Microhardness analysis of Diamond-Like Carbon (DLC) films deposited by PECVD, using R.F. generator was carried out. This analysis was realized by a standard tester PMT-3 which consists of a flat field optical microscope and a diamond stylus probe. Vickers indentation measurements were done with constant loads of: 10 g, 20 g, 30 g, 50 g, 60 g and 70 g in a continuous pressure. It was shown that microhardness results of the DLC thin films are strongly dependent on the methodological principles of the measurement technique and instrumentation. An iterations method was used in order to choose the correct load value. Every loading was accompanied with a metallographical control of the indentor's stamps quality. Best results were obtained for 10 g, 20 g and 30 g loads. The analysis is based on the empirical approach and the "cavity model" of the indentation hardness.