Superhard PVD coatings in the B–N–C triangle

Abstract The boron–carbon–nitrogen (B–N–C) triangle contains the hardest known materials. Sputtering from BN, C and B 4 C targets enables to enter the B–N–C triangle for thin films. Following an overview on possible material properties, the potential of film deposition by magnetron-sputter-ion plating (MSIP)-PVD is outlined. Stoichiometric regions that have been achieved by non-reactive and reactive deposition modes are introduced. Frame conditions to enable advantageous deposition in the direct current (d.c.) mode along the B–C axis are presented. The influence of the deposition parameters to produce ultrahard materials at the B–C axis is demonstrated in detail. Several metal substrates have been coated and tested for suitability. A tribological evaluation is carried out with these films using a modified pin-on-disk-test and Taber abraser to outline wear protection effects on tribosystems with a metal counter part. This work was partially financed by the Commission of the European Community under Brite/EuRam contract BRE2-CT93-0451.