Comparison of the cavitation erosion and slurry erosion behavior of cobalt-based and nickel-based coatings

Cobalt-based and nickel-based coatings were successfully produced using TIG welding and laser cladding technologies as alternative materials with higher cavitation erosion (CE) and slurry erosion (SE) resistance, respectively. Their structure, phase constitution, hardness and elastoplasticity were characterized. Combined with the cumulative mass loss, erosion morphology and roughness, the CE and SE resistances were compared and erosion models were also proposed. The results show that the cobalt-based coating exhibited much better CE resistance and lower SE resistance than the nickel-based coating. The phase transition contributes mostly to the high CE resistance of the cobalt-based coating. While, the combined effects of high hardness, elastoplasticity and hard phases' anchoring and shielding, determine the high SE resistance of the nickel-based coating.