TRIBOLOGICAL STUDY OF CUBIC BORON-NITRIDE FILM

Tribological properties were measured for cubic boron nitride (c-BN), amorphous boron nitride (a-BN) and hexagonal boron nitride (h-BN) films deposited onto a silicon substrate by a magnetically enhanced plasma ion plating method. The friction and wear properties of the films were measured over a wide range of applied vertical loads: from an ultralight load of 1-mu-N to 5 N. The tribological properties were highly dependent on the crystal structures. The c-BN film showed the highest wear resistance of the tested films at all loads of microscopic and macroscopic sliding. The lubricating performance of the c-BN film also proved to be significant, with a long lubricating life and low friction. It is particularly noted that the c-BN film shows good tribological performance under microscopic sliding, because in microtribology, the physical and chemical properties of surfaces are the primary factors, rather than the mechanical characteristics of the bulk material, as is the case in conventional tribology.