Tribological aspects of the Diamond-like carbon film applied to different surfaces of AISI M2 steel

Abstract

This study investigated the influence of the roughness of AISI M2 steel substrate on the mechanical properties and performance of the DLC film exposed to a tribosystems with a hypoeutectic aluminum-silicon alloy, evaluating the adhesion properties, resistance to microabrasive wear and friction coefficient in sliding test. The film was deposited in samples with three distinct roughnesses, depending on the finishing condition: casted, grinded and polished. Results showed that the substrate roughness does not influence the structure of the DLC, but its morphology and tribological behavior. A better adhesion of the DLC was observed in the casted and polished substrates. In the microabrasive test, less wear resistance was found for rougher substrates, the polished substrate showed lower wear rate and specific wear coefficient. In the sliding test, different film behaviors were observed in the running-in and steady state regimes, with the casted substrate responsible for the lowest friction coefficient.