Self-lubricating-diamond-like Coatings Deposition

Ion beam enhanced deposition (IBED) has been used to deposit hard, adherent thin films of boron nitride with a significant cubic crystal structure present. A number of analytical techniques have been used to characterize these coatings including X-ray photoelectron spectroscopy (XPS); X-ray diffraction (XRD); transmission electron microscopy (TEM); Raman spectroscopy; nuclear radiation analysis (NRA); Rutherford Backscattering spectroscopy (RBS); and IR spectroscopy. Friction and wear behavior of these coatings was also conducted. The IBED-i-BN thin films generally exhibit a high microhardness and good adhesion to the silicon and 304 stainless steel substrates. All films (except one) had the hyperstoichiometric boron concentration. The ration Boron/Nitride approached the theoretical value at the highest current densities of the nitrogen beam. Many of the i-BN coatings exhibited low friction against 440 C stainless steel and Silicon nitride counterfaces. Friction seems to increase with increasing B/N ratios. There is a strong demand for diamond-like coatings of boron nitride (BN) in a large number of tribological applications including cryogenic bearings and adiabatic engines. Commercial use of BN coatings has previously been impeded by sample to sample reproducibility problems which have been overcome by the innovative Spire process using ion beam enhanced deposition (IBED). Keywords: Ion beam; Deposition; Boron nitride; Diamond-like; Hardness; Friction. (jg).