Enhancing high-temperature wear resistance of plasma-sprayed NiCrBSi coatings with nanodiamond reinforcement

High-temperature wear causes industrial components to degrade quickly, leading to reduced efficiency, frequent breakdowns, and costly repairs. Thermal spraying is a surface modification technique employed to address these wear issues by shielding the component using protective coatings. In this study, the high-temperature wear behavior of plasma-sprayed NiCrBSi coatings reinforced with Nanodiamond (ND) particles was systematically evaluated. The coatings were reinforced with 1 wt% and 2 wt% ND, and their tribological performance was assessed under varying thermal conditions. Tribological tests were conducted using a ball-on-disk setup at elevated temperatures of 473 K, 673 K, and 873 K for 60 min. The experimental results demonstrated a significant improvement in the wear response and frictional characteristics of the NiCrBSi coatings with the incorporation of ND particles. Specifically, the NiCrBSi coating reinforced with 2 wt% ND exhibited a significantly lower wear volume loss and a reduced coefficient of friction when compared to the pure NiCrBSi coating. At 873 K, the NiCrBSi-2ND coating demonstrated a 64 % reduction in wear volume loss and 85 % decrease in the coefficient of friction, compared to the pure NiCrBSi coating. The incorporation of NDs greatly enhanced the lubrication and hardness of the NiCrBSi-2ND coating as well as improved the adhesion of wear debris to the newly exposed wear track. The high thermal conductivity of NDs enhanced heat transfer to the coatings, facilitating the formation of a protective tribo layer at elevated temperatures, which improved the wear resistance of the NiCrBSi-2ND coating. These findings underscore the potential of ND as a reinforcing agent to significantly enhance the durability and efficiency of NiCrBSi coatings in extreme thermal environments.