HVOF and HVAF Coatings of nano-agglomerated Tungsten Carbide - Cobalt powders for Water Droplet Erosion Application

Thermal sprayed tungsten carbide based coatings have been the focus of many studies ‎and are industrially accepted for a multitude of wear and erosion resistance applications‎. The ‎present work studies the microstructural, phase analysis and mechanical properties such as micro-‎hardness and fracture toughness and their effects on the water droplet erosion resistance of such ‎coatings deposited with thermal spray processes including HVOF (high velocity ‎oxygen fuel) and HVAF (high velocity air fuel). The feed nano-agglomerated tungsten carbide-‎cobalt powders are in either sintered or non-sintered conditions. The WDE tests were performed using 0.4 mm water droplets at 300 m/s ‎impact velocity. The study shows promising results for this cermet as WDE resistant coating when the ‎coating can reach its optimum quality using the right thermal spray process and parameters.