EFFECTS OF HIGH VELOCITY OXY-FUEL (HVOF) PROCESS PARAMETERS ON POROSITY AND MICROHARDNESS OF TITANIA COATING
Keywords:
Titania, HVOF spraying, Response surface methodology, optimizationAbstract
The Titania or Titanium dioxide (TiO2) coating was produced by High velocity oxyfuel (HVOF) spraying on commercially pure titanium substrate. The titania coating has been considered for wear resistance, corrosion resistance and environmental barrier coating. The Titania is a suitable candidate for titanium to protect from wear and corrosion in oxygen reduced environments due to its coefficient thermal expansion match with titanium substrate. The microstructural and mechanical properties of titania coating could be tailored by controlling parameters involved in the thermal spray system. A design of experiments (DOE) method was used to identify the influence of HVOF spray parameters on coating porosity and microhardness. A central composite rotatable design with four factor and five levels was chosen to minimize the number of experimental condition. The response surface methodology (RSM) was employed to describe effects of process parameters such as spray distance, fuel flow rate, oxygen flow rate and powder feed rate on coating porosity and microhardness. The analysis of results shows the major influencing factors to coating porosity and microhardness are spray distance and fuel flow rate.
Downloads
References
Thermal Spray Materials Guide (2007), Sulzer Metco Inc.,.
Kim G E, Walker Jr Williams Jr J B (2006), “Nanostructured titania coated titanium” US Patent Vol., 6835,449 B2.
Miyayama M, Koumoto K, Yanagida H S J, Schneider Jr (Ed.) (1991), “Engineered Materials Handbook Ceramic and Glasses”, ASM International Materials Park, OH, USA, Vol. 4, 748.
Ibrahim A et. al. (2007) “Fatigue and mechanical properties of nanostructured and conventional titania (TiO2) thermal spray coatings” Surface & Coatings Technology, 7589–7596.
Gil L (2002) “Influence of HVOF parameters on the corrosion resistance of NiWCrBSi Coatings” Thin Solid Films, Vol. 420 – 421 ( 446–454).
Forghani et. al. (2013) “Effects of plasma spray parameters on TiO2-coated mild steel using design of experiment(DoE) approach” Ceramics International, 3121–3127.
Jaworski R et. al. (2008) “Characterization of mechanical properties of suspension plasma sprayed TiO2 coating using scratch test” surface coating technology, Vol. 202 (2644-2653).
Shahi A S and Pandey S (2008) “Modelling of the Effects of Welding Conditions on Dilution of Stainless Steel Claddings Produced by Gas Metal Arc Welding Procedures” Journal of Material Processing Technology, Vol. 196 (339-344).
Montavon G et. al. (1997), J. Therm. Spray Technol., Vol-6 (153-166).
Rush W (2007), “Thermal Spray”, Global Coatings Solutions, ASM International, 572.
Josep A and Picas (2013), “Influence of HVOF spraying parameters on the corrosion resistance of WC–Co-Cr, coatings in strong acidic environment”, Surface & Coatings Technology, Vol. 225 (47–57).
Mingheng Li, Panagiotis D and Christofides (2009), “Modelling and Control of High-Velocity Oxygen-Fuel (HVOF) Thermal Spray: A Tutorial Review”, Journal of Thermal Spray Technology, Vol. 18 (5-6) 753-768.
Gaona M (2008), “Influence of particle temperature and velocity on the microstructure and mechanical behaviour of high velocity oxy-fuel (HVOF)-sprayed nanostructured titania coatings”, Journal of materials processing technology, Vol. 198 (426–435).
Kuroda S et. al. (1992), “Significance of Quenching Stress in the Cohesion and Adhesion of Thermally Sprayed Coatings”, Journal of Thermal Spray Technology, Vol. 1 (325-332)
Qun Wang (2012), “The parameters optimization and abrasion wear mechanism of liquid fuel HVOF sprayed bimodal WC– 12Co coating”, Surface & Coatings Technology, Vol. 206 (2233–2241).
Gil L (2002), “Influence of HVOF parameters on the corrosion resistance of NiWCrBSi Coatings”, Thin Solid Films, Vol. 420 – 42, (446–454).
Ramachandran C S, Balasubramanian V and Ananthapadmanabhan P V (2006), “Multiobjective Optimization of Atmospheric Plasma Spray Process Parameters to Deposit Yttria-Stabilized Zirconia Coatings Using Response Surface Methodology”, ASM International.
Tien C L, Lin S W (2006), “Optimization of process parameters of titanium dioxide film by response surface methodology”, Optical communication, 574-581.
