Phase Composition and Tribological Behaviour of Titanium Boron Nitride Coatings

There is a growing interest for thin film coatings for dry machining technologies which display both high hardness and low friction properties. Ti-B-N coatings are multiphase coatings and can be deposited in such a way that they contain the two hard phases TiB2 and TiN, and in addition the soft and lubrificating hexagonal BN phase. By a suitable choice of the relative content of these phases coating properties can be tailored. In this paper we examine two types of coatings: 1) homogeneous multiphase Yi-B-N coatings by reactive sputtering from a TiB2 target; 2) coatings of the same type in which carbon ions have been implanted (Ti-B-N-C). Bonding type and phase composition were determined by photo electron spectroscopy and glancing angle X-ray diffractometry. Hardness measurements were performed by nanoindentation, and friction tests were carried out using both the pin-on-disk and pin on-flat geometry with a 100Cr6 steel ball as the counterface. Ultra hard coatings were obtained if the coatings were composed of the two hard phases TiB2 and TiN, but the addition of the BN phase produced no lubricating effect. However, carbon implanted Ti-B-N layers showed a strong reduction of the friction coefficient.

GISSLER Wolfram;  HAUPT Justus;  GIBSON Peter Neil;  GILMORE Richard;  MOLLART Timothy Peter; 

1996-07-30

JRC13438

https://publications.jrc.ec.europa.eu/repository/handle/JRC13438,