Hydroxyapatite (HAP) is available in powder form for plasma spraying. HAP powder was fabricated indigenously in the Rod form of diameter 4.17mm. This rod was sprayed with the help of MEC make Rodojet 9810 (flame spray process). Rodojet parameter were optimised for HAP rod. Crystallinity and purity level of HAP rod was measured. XRD and SEM were used to analysed the microstructure of rod and coating. The microstructure, mechanical properties of the coating were investigated, and measure the Ca/P ratio of coating and rod. The micro-hardness and elastic modules were determined by indentation tests and bond strength was determined by tensile test. The results showed that the microstructure, mechanical properties was observed same as in plasma spray process. Porosity was observed more than 15%. The bond strength of coating was observed 20 MPa. Scratch test was done to measure the cohesive strength of coating. This new experiments play an important role for reduction the cost of the HAP powder coating.

This paper discusses the modification of powder feeders to facilitate the deposition of nano materials by thermal spraying without the use of a suspension or solution precursor. Two powder feeder designs were developed and used to deposit nanocarbide coatings by HVOF spraying. The nano coatings were examined and tested, and the results are presented and discussed.

This study compares high-velocity oxygen fuel spray MJP5000 and MJP 6000 (Patented by Metallizing Equipment Company Pvt Ltd.) using powder WC-Co-Cr. The microstructure and phase composition of powders and coatings will be analyzed by scanning electron microscopy and X-ray diffraction. Coatings were also characterized by their hardness, bond strength, roughness, deposition efficiency. Therefore, coating of high hardness and wear resistance can be produced with all HVOF spray system when the proper spray powder and process parameters are chosen. The results demonstrate that the powder exhibits various phase transformation during the spray process depending on type of powder, spray system and spray parameters.

High velocity oxy fuel thermal spray (HVOF) processing is one of the proven thermal spray technologies to develop high temperature oxidation and corrosion resistant coatings for various high temperature applications such as thermal power plants, aero turbines, and energy conversion systems. In the present investigation Nickel based coatings, viz. Ni-5Al, NiCrAl, and NiCrAlY-0.4wt%CeO 2 were sprayed on Fe based superalloy (Superfer 800) by HVOF spray process as the chosen superalloy finds extensive use steam boilers, furnace equipment, heat exchangers and piping in chemical industry The degradation behaviour of the coated superalloy was studied in the aggressive environment of 40%Na 2 SO 4 -60%V 2 O 5 at 900°C, using thermogravimetric technique, to understand the protective nature of the coatings under cyclic conditions. The coatings were found to be effective in increasing the resistance to the degradation in the given environment. Among the coatings investigated, NiCrAlY-0.4wt%CeO 2 coating was found to be more protective on the superalloy in the given aggressive environment. The corrosion mechanisms were elucidated through the X-ray diffraction (XRD) analysis and microstructural characterization techniques such as FE-SEM/EDAX analysis of the corroded products formed at high temperature.

A new variant of LVOF system was developed to deposit ceramics. For this study Cr 2 O 3 powder was used. To save on time and reduce mathematical iterations optimizing of parameters was carried out by using an online particle diagnosing system. The spray parameters were varied to study their influence on the particle in-flight characteristics. The parameters which gave best particle temperature and velocity was used for coating. The resulted coating was dense and hard.