High-velocity oxygen fuel (HVOF) thermal spraying uses a combustion process to heat the gas flow and coating material. A computational fluid dynamics (CFD) model has been developed to predict gas dynamic behavior in a HVOF thermal spray gun in which premixed oxygen and propane are burnt in a combustion chamber linked to a parallel-sided nozzle. The CFD analysis is applied to investigate axisymm...

This work evaluates the suitability of iron aluminide coatings for use in high temperature fossil fuel combustion environments, such as boiler applications. The coatings are applied using High Velocity Oxy-Fuel (HVOF) thermal spray techniques. Bulk Fe3Al coatings are known to exhibit excellent oxidation and sulfidation resistance at high temperatures, however, the behavior of HVOF-deposited Fe3...

A nanostructured hydroxyapatite (HA) feedstock was thermally sprayed on Ti–6Al–4V substrates via high velocity oxy-fuel (HVOF process). The particle temperature and velocity for the HA particles in the HVOF jet were monitored during spraying and found to be 1826± 346 ◦C and 638± 82 m/s, respectively. The bioactivity of the coating was investigated in a simulated physiological environment, as an...

The high energy ball milling technique permits production of composite powders suitable for application in thermal spray processes. Different milling systems are compared concerning their potential for production of composite powder feedstock for spraying processes. Hard phase materials like carbides or oxides are incorporated into various metallic matrices including light weight alloys based o...

The improvement and mechanism of the fatigue resistance of TC21 high-strength titanium alloy with a high velocity oxygen fuel (HVOF) sprayed WC-17Co coating was investigated. X-ray diffraction (XRD) and the corresponding stress measurement instrument, a surface roughness tester, a micro-hardness tester, and a scanning electron microscope (SEM) were used to determine the properties of the HVOF W...

Power particles are mainly in solid state prior to impact on substrates from high velocity oxyfuel (HVOF) thermal spraying. The bonding between particles and substrates is critical to ensure the quality of coating. Finite element analysis (FEA) models are developed to simulate the impingement process of solid particle impact on substrates. This numerical study examines the bonding mechanism bet...

In this study, the newly designed bipolar plate for proton exchange membrane fuel cells (PEMFC) was produced by spray-coating the Ni65Cr15P16B4 metallic glassy alloy on Al plate. The Ni65Cr15P16B4 metallic glass was adopted as a coating material because of its excellent corrosion resistance and the high velocity oxy-fuel (HVOF) spray coating was used for the metallic glass deposition on the Al ...

Thermal spray has traditionally been used for depositing metallic, carbide and ceramic coatings, however, it has recently been found that the high kinetic energy of the High Velocity Oxy-Fuel (HVOF) thermal spray process also enables the solventless processing of high melt viscosity polymers, eliminating the need for harmful, volatile organic solvents. A primarily goal of this work was to devel...

This work focuses on the modeling and feedback control of the high velocity oxygen fuel (HVOF) thermal spray processing of WC–Co coatings. A first-principles-based process model is proposed to explore the fluid dynamics and particle inflight behavior in the HVOF flow field. Rule-based stochastic simulation, which encapsulates the main features involved in the deposition process, is used to capt...