Ultra-hard Ti–B–N coatings obtained by magnetron sputtering

Abstract Titanium boronitride coatings were deposited by reactive magnetron cosputtering. The Ti and the TiB 2 targets were sputtered by using an Ar–N 2 gas mixture. The deposition configuration allowed us to obtain a composition gradient along the substrate length. The coatings have been characterized by reflectivity measurements and X-ray diffraction while, for mechanical applications, scratch tests, hardness indentations and wear tests were used. The zone explored in the Ti–B–N diagram shows very different behavior with chemical composition. Coatings 10 μm thick with 6000 HV hardness exhibit wear rates nine times lower than those of TiN coatings.