Laser Plasma-Chemical Deposition of Hafnia-Doped Solid Silicon Carbonitride Coatings

Solid hafnia-doped silicon carbonitride coatings are synthesized using laser plasma in a high-speed argon flow from hexamethyldisilazane (HMDS) Si2NH(CH3)6 and hafnium dipivaloylmethane Hf(dpm)4 vapor mixture. The coatings are characterized by X-ray photoelectron, IR, and Raman spectroscopy techniques. The structural studies are carried out by powder XRD; the coating hardnesses are measured by nanoindentation. The hardness of the coatings synthesized on stainless steel from a HMDS and Hf(dpm)4 mixture is 21-24 GPa at a Hf(dpm)4 concentration of up to 2.5 wt. % and decreases to 7 GPa if the Hf(dpm)4 content increases in a mixture to 4.5 wt. %.