High Velocity Oxy-Fuel (HVOF) as a materials test method for simulating aerothermal effects

Abstract

High Velocity Oxygen-Fuel (HVOF) is a member of the thermal spray process family in which a mixture of oxygen, fuel, and compressed air are continuously combusted and the resulting flame is accelerated through a nozzle to achieve high gas velocities. HVOF is most commonly used to heat (to the point of melting) and accelerate powder particles towards a substrate to apply coatings. Here, HVOF is presented as a method for simulating high-speed aerothermodynamic effects. With gas velocities in the low Mach regime and gas temperatures exceeding 2000°C in an oxidative environment, HVOF is a promising low- cost test method for screening high temperature materials and components. Three examples of experiments based on using HVOF as a test method are presented, including low thermal conductivity thermal barrier coatings, thermal protection system materials for solid rock motor exhaust environments, and evaluation of high temperature ceramics and glass-ceramic composites