Facile fabrication of Co-containing coating to enhance the wear resistance of 24CrNiMo steel at elevated temperature

High-speed train brake discs, relying on surface friction for braking, can reach up to 600 °C, significantly increasing wear and adversely affecting performance and lifespan. Here, we propose a facile approach employing ultrasonic shot peening with the addition of cobalt (Co) particles (termed UEG) to creates a dense Co-containing coating on the 24CrNiMo steel. Friction tests show that UEG samples exhibit more stable friction coefficients and lower wear rates at temperatures ranging from 25 to 600 °C. Experimental and analytical results reveal a higher dislocation density in the UEG-treated samples surface and the formation of a dense Co-enriched tribofilm, effectively enhancing wear resistance. The findings indicate that UEG has considerable promise for enhancing the wear resistance of brake discs in high-temperature environments.