Papers by Keyword: High Velocity Oxy-Fuel (HVOF)

Abstract: Combustion gas of gas turbine is about 1100 ~ 1300 °C. Is doing TBC(Thermal Barrier Coating) on the base metal surface to protect rotor or blade from high temperature flame. TBC system reduced heat transfer as metal base metal. TBC system is divided by bond coating of prevent oxidation and corrosion and Top coating reduced of heat transfer by high Temperature flame. The objective of this study was to development of an advance TBC system for high Temperature (>1350°C) gas turbine components. Used coating powder developed newly in coating process, and more than 1350°C by parameter control in usable coating method develop. Internal studies looked at the effect of TBC coating thickness, material chemistry, substrate composition, surface temperature and bond coat as-sprayed surface profile/particle size on technical performance.

Abstract: Hydroxyapatite (HA) coatings are widely used to improve the biocompatibility of titanium substrates. The main problem concerning these coatings is related with the bad adhesion characteristic of the ceramic/metal interface. A TiO2 interlayer can be used to improve the adhesion of the coating; however the TiO2 is a bioinert material. Then, a solution can be the use of a mixture of HA-TiO2 (60% wt HA- 40% wt TiO2) powder has been sprayed by using High Velocity Oxy-Fuel (DJH-2700) for different spraying distances. The adhesion of the coatings has been mechanically tested and the values have been compared with the values obtained for coatings that have been immersed in simulated body fluid solution (SBF) after 24 and 120 hours. The crystallinity degree of the HA plays an important role on it for the dissolution affecting the behaviour of the interface at the same time it is also important osteoclastic resorption and carbonate apatite precipitation.