HVOF ceramic coatings

A secondary acetylene after burner attached with an HVOF gun has been developed to produce high quality coatings required of ceramics. The secondary burner adds heat energy, enough to make deposition, to fine ceramic particles heated and accelerated by an HVOF gun. The energized particles are still not fully melted but just softened or partially melted on the surface and accelerated at as high as jet flame velocity. The coatings produced by this way present extremely unique characteristics, quite unlike from plasma coatings or D-gun coatings. The phase transformation in coatings is very little observed. The porosity is negligible. The resistant to wear and the density are very close to those of the bulk. This paper will present significant features of HVOF ceramic coatings in comparison with plasma coatings.