Study of a-C:H thin films grown by PIII in different times for Mechanical and Tribological applications

Abstract

A Steel alloy (16MnCr5) used for automotive applications (engine components) was chosen as substrate to be covered by DLC films deposited by Plasma Immersion Ion Implantation. This kind of recovery is useful for improve its mechanical and tribological applications, more specific to increase surface hardness and to reduce the friction coefficient (µ). After polished and ultrasonicated, 16MnCr5 substrates were submitted to PIIID procedures for 100 W of radiofrequency power, from atmospheres supplied with 80 % of methane and 20 % of argon, keeping the work pressure fixed to 5.5 Pascal. Four different deposition times was chosen being of (1800 s, 3600 s, 5400 s and 7200 s). PIII parameters were (-3600 V, 30 µs and 300 Hz). It was investigated the effect of DLC properties over the substrates using Raman Spectroscopy (for Hydrogen content and microstructure analysis), Ultra Micro-Tribometer (for friction coefficient: µ) and Nanoindentation (hardness).