Process and Coating Performance Comparison of High Velocity Combustion Spray Systems

The high velocity oxy-fuel (HVOF) process emerged in the late 1980s and has become established within the realm of thermal spray technology. A more recent variation of HVOF is the high velocity air-fuel process (HVAF), which uses air as the oxidizing medium in lieu of oxygen, and has recently become more industrialized. HVAF coatings are typically utilized for hard-facing in oil and gas, mining, and industrial wear applications while HVOF has broader acceptance in other markets such as aerospace and power generation. In this work, a preliminary investigation on process metrics, and coating structure/performance is conducted on tungsten carbide based coatings produced using several different feedstock powders for the two spray processes. Process metrics include efficiency, throughput, logistics and practicality. Coatings will be evaluated on the basis of microstructural characteristics as well as wear and corrosion performance.