Plasma spraying of zirconia–titania–silica bio-ceramic composite coating for implant application

Zirconia–titania–silica (ZTS) bio-ceramic composite coating was deposited on titanium surface via plasma spray process. The original feedstock was prepared by mixing equal amounts (wt.%) of each powder in ceramic pot followed by stirring with ceramic ball. The resulting composite powder was sprayed at two different stand-off distances (SOD: 45 and 50 mm). Silica particles are distributed uniformly in the coating matrix. Amorphous silica was detected by energy-dispersive X-ray spectroscopy (EDXS) and FT-IR analysis which showed the spectra of Si–O and Ti–O stretching bonds. Anatase phase, the main phase of titania in feedstock, was transformed into rutile phase in the coating structure. The spraying efficiency was increased as the stand-off distance decreased. High intensity of tetrahedral zirconia phase was detected in the composite coating sprayed at 50 mm SOD.