Development Of Processing Windows For New Generation HVOF Carbide-based Coatings

This paper discusses the development of optimised processing windows for spraying new generation, high quality carbide cermet coatings using advanced particle diagnostic technologies. The cermet coatings are produced via the high velocity oxygen fuel spray process (HVOF) and are intended to be used severe service applications such as marine hydraulics. To develop suitable coating process parameters, the traditional “trial and error” methodology is not technically robust, is costly and time consuming. Instead we investigated the use of real-time monitoring of parameters associated with the HVOF flame jets and particles using advanced inflight particle diagnostic. Subsequently, coatings can be produced with the knowledge of the molten particles size, temperature and velocity profile. The analytical results allow identification of optimised coating process windows, which translate to coatings of lower porosity and good mechanical performance.