High-velocity oxy-fuel spraying

Melero, H., Fargas, G., Garcia-Giralt, N., Fernandez, J., and Guilemany, J.M. (2014b) Mechanical performance of bioceramic coatings obtained by high-velocity oxy-fuel spray for biomedical purposes. Surf. Coat. Technol., 242, 92-99. 

T.S. Sidhu, R.D. Agrawal, S. Prakash, Hot corrosion of some superaUoys and role of high-velocity oxy-fuel spray coatings-a review. Surf Coat. Tech. 198 (2005) 441-446. 

Sidhu TS, Agarwal RD and Prakash S, Hot Corrosion of Some Super Alloys and Role of High-Velocity Oxy-Fuel Spray Coatings. Surf Coat Technol, 2005, 198 441-446. 

Gas-phase spraying, high-velocity oxy fuel spraying Physical vapor deposition Thermal evaporation ... 

Edris, H., Mccartney, D. G. and Sturgeon, A. J. 1997. Microstructural characterization of high velocity oxy-fuel sprayed coatings of Inconel 625. Journal of Materials Science, 32, 863-872. 

A steady-state rocket-type combustion spray unit has been developed, called high velocity oxy fuel (HVOF), that creates a steady state, continuous, supersonic spray stream (1.2—3 mm dia) resembling a rocket motor exhaust. The portable device injects and accelerates the particles inside a barrel (rocket nozzle). It produces coating quaHty and particle velocities equal to the D-gun at 5—10 times the spray rate with significantly reduced coating costs. 

Thermal Spray Surface Coating and Free-Standing Components - Plasma Spray - High Velocity Oxy-Fuel (HVOF)... 

It can be assumed that coatings formed from lower crystallinity particles exhibit low residual stress because feedstock also has inherent porosity that would tend to relieve process-induced stresses. A comparison of the high velocity oxy-fuel and plasma spray processes has revealed that the residual stress is lower in the former process (Knowles et al. 1996). Heat treatment at temperatures of 800°C can minimize these process-induced stresses (Brown et al. 1994). Despite the large influence of thickness on coating strength, no difference in bone apposition has been found for 50 pm and 100 pm coatings. 

Jeffcat, Catalysts, Huntsman Corp., Headquarters Jenite, White rigid vinyl. Kings Specialty Jet Kote, High-velocity oxy-fuel thermal-spray system. Stellite Coatings... 

Table 1 lists the wear coatings which have been under evaluation to this point in the program. Wear testing has been completed for almost all the air plasma sprayed (APS) chromium oxides, some of the high velocity oxy-fuel (HVOF) thermal sprayed materials and the slurry-sprayed silica-chromia-alumina (SCA). Microstructural characterization has been completed for all the coatings which have been wear tested. 

Figure 15.4 Mapping electrochemical material loss against mechanical erosion rates for a nonpassivating surface carbon steel (AISI1020) along with two potentially passivating surfaces of nickel aluminum bronze (NAB) one that has been thermally sprayed by high-velocity oxy-fuel deposition as a coating on carbon steel ( j and another which has been cast (A.). These results were obtained from jet impingement erosion-corrosion tests. Reprinted from Ref. [7]. Copyright (2007) with permission from Elsevier.

The "hybrid spray" process utilized in this study was conceptualized in our laboratory at the University of Michigan (Kosikowski et al., 2005). This process combines the arc and high velocity oxy fuel (HVOF) spray techniques molten metal at the arcing tip is atomized and rapidly propelled to the substrate by a HVOF jet. This so called "hybrid" concept shown in Fig. 5 offers many advantages. 

Lau, M. L., Gupta, V. V. and Lavemia, E. J. 1999. Particle behavior of nanocrystalline 316-stainless steel during high velocity oxy-fuel thermal spray. Nanostructured Materials, 12, 319-322. 

There are three basic categories of thermal spray technologies combustion torch (flame spray, high velocity oxy-fuel, and detonation gun), electric (wire) arc, and plasma arc. Thermal spray processes are maturing, and the technology is readily available. 

Accordingly, Schadler et al. employed a high-velocity oxy-fuel (HVOF) system to thermally spray Si02 (7 and 12nm)/nylon 11 nanocomposite coatings. Polymerization filling (i.e. monomers polymerized in the presence of fillers) is an effective approach to ensure intimate contact between the fillers and the matrix. Cai et al. synthesized carbon nanotube/polyimide (PI), nano-Al203/... 

Picas J A, Forn A, Igartua A, Mendoza G, Mechanical and tribological properties of high velocity oxy-fuel thermal sprayed nanocrystalhne CrC-NiCr coatings . Surf Coat Technol, 2003, 174(9/10), 1095-1100... 

Chan TL, Rouhana SW, Mulawa PA, Reuter RJ. Occupational health assessment of the high velocity Oxy-fuel thermal metal spray process. Appl Occup Environ Hyg 1995 10 482-487. 

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