Microstructure and corrosive wear behavior of Fe-based amorphous coatings prepared by extreme high-speed laser cladding

This study investigates the effect of scanning speed on Fe-based amorphous coatings produced by extreme high-speed laser cladding at 35, 45, 55, and 65 m/min. Elevating scanning speed to 65 m/min increased amorphous phase content by 54.5% relative to 35 m/min, driven by a rapid solidification cooling rate of about 27,488.75 °C/s verified via in-situ infrared thermography. Enhanced amorphous retention improved mechanical properties, yielding a 51.9% microhardness increase and superior dry wear resistance. Tribological analysis revealed a 25.9% friction coefficient reduction and 51.8% lower mass loss at 65 m/min, with wear mechanisms transitioning from abrasive to oxidative-abrasive modes. Electrochemical testing demonstrated a 21.8% higher self-corrosion potential and 29.2% lower corrosion current density for 65 m/min coatings compared to 35 m/min counterparts, confirming enhanced corrosion resistance. Corrosive wear resistance improved significantly, exhibiting 65.9% lower wear loss and 63.0% reduced wear rate at elevated speed. The results demonstrate that kinetic control inherent to this process increases the amorphous fraction and delivers simultaneous improvements in mechanical durability and electrochemical stability through rapid thermal quenching and suppression of defect formation, providing critical guidance for the design of high-performance coatings for severe service environments.