Modeling and Control of High-Velocity Oxygen-Fuel (HVOF) Thermal Spray: A Tutorial Review

Abstract

This work provides a tutorial overview of recent research efforts in modeling and control of the high-velocity oxygen-fuel (HVOF) thermal spray process. Initially, the modeling of the HVOF thermal spray, including combustion, gas dynamics, particle in-flight behavior, and coating microstructure evolution is reviewed. The influence of the process operating conditions as predicted by the fundamental models on particle characteristics and coating microstructure is then discussed and compared with experimental observations. Finally, the issues of measurement and automatic control are discussed and comments on potential future research efforts are made.

A Comprehensive Review on Fluid Dynamics and Transport of Suspension/Liquid Droplets and Particles in High-Velocity Oxygen-Fuel (HVOF) Thermal Spray

“…The powder can be injected into the jet in radial or axial directions using a carrier gas which is usually nitrogen or argon [1]. The HVOF system can be used to spray metals, metallic alloys, cermets, ceramics, and polymers [1,4,6,8,9]. However, particles are usually composites with carbide reinforcements, metals, and alloys, and are in the range of 5-45 µm [1].…”

“…Obviously, the particle temperature and melting state and its kinetic energy have enormous influence on the coating properties. Therefore, the temperature, trajectory, and velocity of these fine particles must be well controlled to generate repeatable and desirable coatings [1][2][3][4].…”

“…The HVOF coatings have been widely applied in industries such as in coating piston rings and cylinder bores in the automotive industry, rolls and blades in the pulp and paper industry, ball and gate valves in the process industry, and the production of thermal barrier coatings for turbine sections and landing gears in the aerospace industry. The HVOF system is able to generate anti-corrosion protective coatings that are useful in the energy industry particularly to protect power plant boilers [4][5][6]. The main physical phenomena involved in the HVOF process and the available numerical approaches for its simulation are not discussed in detail in the previous review papers [4,5].…”

“…The HVOF system is able to generate anti-corrosion protective coatings that are useful in the energy industry particularly to protect power plant boilers [4][5][6]. The main physical phenomena involved in the HVOF process and the available numerical approaches for its simulation are not discussed in detail in the previous review papers [4,5]. Therefore, the focus of this review is to explain these phenomena and the numerical methods comprehensively to prepare an all-inclusive document for simulation, design, and optimization of the HVOF torch.…”

Ni‐Ti Shape Memory Alloy Coatings for Structural Applications: Optimization of HVOF Spraying Parameters

“…Among the several technologies for depositing metallic coatings on metallic substrates, thermal spray high-velocity oxygen-fuel (HVOF) is one of the most versatile [8] and efficient technologies, with many multiscale features [9,10], capacity to produce homogeneous [11] and very dense coatings [12][13][14][15][16][17] with porosity levels typically in the range 0.1-2% [13], low oxide content [11,12], high hardness [13,18], excellent bond strength frequently exceeding 69 MPa [11,13,19], and low decarburization [13,20]. Also, the low gas temperature of particles avoids superheating during flight and preserves the nanocrystalline structure of the starting powders of the coating [21].…”