Electron-beam synthesis of ceramic- and boron-based coatings

Abstract

We report the results of our experimental investigations on the synthesis of coatings based on various ceramics and boron. The coatings were synthesized by electron-beam evaporation of solid dielectric targets of Al2O3, YSZ, Al2O3Cr, and B. The deposition rates for coatings based on these materials were measured. The deposition rate of defect-free coatings was 1200-1600 nm/min. The obtained coatings, up to 5 µm thick, were studied in terms of their morphology, structure, and tribological properties. The coatings are uniform in thickness, composition and free of impurities. The coatings, with the exception of the zirconium oxide film, have a predominantly amorphous structure. Comparisons of their mechanical and tribological characteristics are presented. The hardness of the coatings formed from YSZ was 0.4 GPa, from aluminum oxide ceramics 4-6 GPa, and from boron 11 GPa. Boron-based coatings were found to be the most wear-resistant (with wear coefficient about 8.9•10-6 mm3/N•m)