INTERFACIAL STRUCTURE CONTROL OF CUBIC BORON-NITRIDE FILMS PREPARED BY ION-BEAM-ASSISTED DEPOSITION

Boron nitride films were prepared by ion beam assisted deposition (IBA D). The films were synthesized by depositing boron vapor under simulta neous bombardment with nitrogen ions and nitrogen-argon mixture ions. Cubic boron nitride (c-BN) films with enhanced tribological properties had been explored by inserting a B-rich layer as a controlled buffer at the interface. Tribological characterizations of the buffer layer a nd the double-layered BN films consisting of the c-BN layer underneath with the B-rich buffer layer have been performed. Successful growth o f c-BN layer has been observed on the B-rich layer and the hardness of the films increased almost linearly with increasing fraction of the s p(3) bonded cubic phase in the c-BN layer, The control of the interfac ial structure exhibited a significant effect on the improvement of the tribological properties of the films due to the effective relaxation of internal stress of the c-BN films.