Superhard PVD coatings in the B-N-C triangle

The boron-carbon-nitrogen (B-N-C) triangle contains the hardest known materials. Sputtering from BN, C and B4C 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. (C) 1999 Elsevier Science Ltd. All rights reserved.