A. A. Verstak, Kermetco LLC, Concord, CA; V. E. Baranovski, UniqueCoat Technologies LLC, Oilville, VA
Activated Combustion HVAF (AC-HVAF) spraying provides efficient deposition of metallic and carbide coatings using solid particle spray technology. Oxidation and thermal deterioration of sprayed materials is significantly reduced, resulting in improved quality of coatings. Resistance of different WC-Co and WC-Co-Cr AC-HVAF coatings to abrasive wear was investigated using ASTM G-65 test. It was found that the AC-HVAF hardware setup, type of fuel gas and spray parameters affected deposition efficiency but not wear resistance of coatings. Herewith, method of powder manufacturing revealed significant influence on coating wear resistance. The AC-HVAF sprayed coatings were compared to HVOF-sprayed counterparts, as well as to hard surfacing and chrome plating. The AC-HVAF sprayed coatings were efficient in competing with modern surfacing technologies in many industrial applications.
Summary: AC-HVAF sprayed tungsten carbide coatings revealed improved resistance to abrasive wear. Coating properties appeared not sensitive to spray parameters, but were affected by a spray powder manufacturing method. High level and consistency of coating quality as well as favorable economical aspects provided efficient competition of AC-HVAF spraying with other hard surfacing technologies.