An AlCoCrFeNi_2.1 high-entropy alloy coating with uniform microstructure and high hardness

Anisotropy in a thicker coating due to different cross-sectional microstructures is usually a major concern when used for an engineering application. Here, we report that extreme high-speed laser cladding (EHLC) can fabricate coating with thickness of dozens and hundreds microns, whose microstructure and hardness are uniform. Due to lower heat input and rapid cooling, the microstructures with same growth direction under the EHLC are confirmed to connect each other. Based on our present investigation, the EHLC technique opens new avenues for fabricating coatings especially for high-entropy alloy coatings in which uniform microstructure and hardness are required.