Microstructure, Corrosive-Wear, and Electrochemical Properties of Laser Cladded NiCoCrAlY Coatings by Heat Treatment

Abstract

Heat treatment plays a positive role in alloy coatings during the corrosive-wear and electrochemical process, in which the heating temperature is a key factor in the improvement of microstructure. In this work, the laser-cladded NiCoCrAlY coating is processed by heat treatment, and the effects of heating temperature on the microstructure, corrosive-wear, and electrochemical properties of obtained coatings are investigated. The results show that the average coefficients of friction and wear rates of NiCoCrAlY coatings are decreased with the increase of heating temperature, and the wear mechanism is mainly abrasive wear, adhesive wear, and pitting corrosion. Moreover, the corrosion resistance of NiCoCrAlY coatings is decreased with the increase of heating temperature, which is attributed to the precipitation of phases along the grain boundaries at high temperatures.