Investigation of mechanical properties of CrN-PVD thin films by nanoindentation

The hardness of PVD thin films is of great interests regarding to their applications. It is well known that the hardness is influenced by different deposition energies. For the present work, two different coating processes were used to deposit a CrN layer on high speed steels type HS 6-5-2 (M2). The deposition processes were carried out by the Cathodic Are Ion Plating Process (AIP) and the Magnetron Sputter Ion Plating Process (MSIP) by varying the deposition energy. The AIP process was used to deposit coatings under a strong ion bombardment. Magnetron Sputtering was used for comparison with the AIP process. The MSIP process is distinguished by a lower emission of ions in contrast to the AIP process. To evaluate the film hardness of CrN PVD coatings the Nanoindenter(TM) XP was used taking into account the different deposition energies and ionization levels as characteristics of the used deposition processes. A strong chromium ion bombardment leads to a homogenous and uniform coatings structure. As shown in this paper, the film hardness is mainly influenced by the coatings microstructure generated by different deposition energies.