Wear Protection of Engine Parts at High Temperatures by a Co+Cr2O3 Dispersion Coating

Co+Cr₂O₃ is a composite coating of a cobalt matrix with 30 percent by volume embedded Cr₂O₃. The coating can be applied by plating using a suspension of Cr₂O₃ in a cobalt electrolyte. The mechanical properties of this coating are discussed. The main attribute is the excellent wear resistance of the coating especially in the temperature range of 300 to 700°C. Adhesive wear of unplated counterparts is reduced by the same amount. In contrast to nickel the fatigue strength of Co+Cr₂O₃ coated Waspaloy was shown to be not influenced, when heat treated at 400°C for 16 hours. Plated engine parts demonstrate the usefulness of the Co+Cr₂O₃ composite coatings for wear protection.