Surface Properties and Adhesion Behavior of PVD Thin Film Using Multi-cyclic Nanoindentation and Scratch Test

PVD thin film based on chromium nitride was deposited on XC100 steel substrate with reactive radio frequency magnetron sputtering. Thin film was characterized in terms of both surface properties and adhesion behavior. The characterization of surface properties was based on the measurement of mechanical properties coupled with a preliminary microstructural study using SEM and AFM. Fatigue resistance was considered as an important surface properties and it was investigated using multi-cyclic nanoindentation test. Results indicated that chromium-based coatings have a smooth, dense and compact microstructure with a grain size of about 109 nm and a roughness of about 11 nm. CrSiN showed a high adhesion quality, critical loads were LC1 = 16 N, LC2 = 20 N and LC3 = 25 N. PVD coatings exhibited a hardness of about 30.52 GPa and Young’s modulus of about 338.32 GPa. Moreover, multi-cycle nanoindentation technique, with variation of loading mode (progressive and quasi-static) and loading rate (from 200 mN/mn, 400 mN/mn and to 600 mN/mn) was used to analyze superficial fatigue behavior and surface resistance. Whatever, the cyclic loading mode, an elasto-plastic behavior was observed and an appearance of hysteresis loops in the unloading-reloading curves witch was explained by a fatigue effect. In addition, a hardening phenomenon was found when the loading rate increase.