Effect of PVD process parameters on nucleation and structure of CrN layers

Imperfections on substrate surfaces can cause growth defects in hard coatings prepared by magnetron sputtering, leading to local loss of adhesion, higher friction,voids and corrosion at coating defects. CrN-coatings are known for their high hardness and good wear resistance. In addition CrN-coatings are better corrosion resistant than Ti based nitrides. The structure and the mechanical properties of those coatings can be influenced by varying bias voltage and gas flow during film growth. Due to variation of those parameters CrN-coatings were deposited with preferred crystallized lattice orientations (111) and (200). The main objective of investigation is the potential to cover imperfections. Vickers indentations (HV 0.5) were applied as designed imperfections. As base material low alloyed steel was used (100Cr6). At first crystallized lattice orientations were identified by X-ray diffraction (XRD). Further scanning electron microscope analysis (SEM) was applied to identify and study crystallized lattice orientations near those imperfections.