Enhancement of high-entropy alloy coatings with multi-scale TiC ceramic particles via high-speed laser cladding: Microstructure, wear and corrosion

Ceramic-reinforced high-entropy alloys (HEAs) synergize the exceptional plasticity and corrosion resistance of HEAs with the superior hardness and wear resistance of ceramics, offering substantial potential for industrial applications. This study utilized a high-speed laser cladding (HLC) process, achieving a dilution rate of less than 1% and forming metallurgical bonding through optimized parameters. The research focused on TiC ceramic particle-reinforced HEA coatings, examining the effects of incorporating TiC particles at micron, submicron, and nanoscale dimensions on the microstructure, wear resistance, and corrosion resistance of the coatings. Results indicate that the HEA coating exhibits a hypoeutectic structure, with TiC particles of various scales embedded in the interdendritic eutectic regions. Micron-sized TiC particles tend to dislodge during wear, causing micro-shearing and localized galvanic corrosion. Coatings with nanoscale TiC particles exhibit brittleness, leading to inevitable cracking during the HLC process and severe crevice corrosion due to the formation of oxygen concentration cells. Notably, coatings reinforced with submicron TiC particles achieved the best balance of properties. These coatings exhibited superior wear and corrosion resistance due to improved hardness and the enhanced stability of the passivation film. This optimization significantly enhances the reliability and service life of ceramic-reinforced HEAs in demanding industrial environments.