Effects of nanoscale powder on coating deposited by axial plasma spraying TiB₂/Al₂O₃ composite powders

TiO₂/Al₂O₃ composite coatings were deposited by axial plasma spraying (Mettch Axial-Ⅲ):one of feedstock powders was conventional micrometer powder derived from self-propagating high temperature synthesis process, and the other was fabricated by spray-drying TiO₂/Al₂O₃ composite powder doped with 10% mass fraction nanosize Al₂O₃ powder.Microstructure and wear resistance of two type coatings were compared, and effects of nanoscale powder on the coatings were investigated.Scanning electron microscope and X-ray diffraction analysis were used to analyze the sprayed coatings, and disc abrasive wear apparatus was employed to test wear resistance of the coatings. Results show that density and wear resistance of sprayed coating from spray-drying powder are better than that from conventional powder, TiO₂ content is also less than that in the coating from conventional powder, and superficial Rockwell Hardnesses of two coatings are about the same.