Effect of ultrasonic high-frequency percussion on the microstructure and corrosion resistance of Fe-based alloy coatings by high-speed laser cladding

Fe-based alloy coatings were prepared by high-speed laser cladding (HSLC) technology, and the surface was subjected to ultrasonic high-frequency percussion (UH-FP). The dendrites at the top of the coatings were smaller, and there was dendrite segregation. After UH-FP, the surface profile of the coatings was smoother, achieving the mirror effect. The roughness decreased from 2.643 mu m to 0.913 mu m and the residual stress of the coatings changed from 306.92 MPa to -92.18 MPa. The electrochemical corrosion behavior in a 3.5 % NaCl solution indicates that the UH-FP coatings exhibit higher corrosion resistance. Anti-corrosion mechanism was discussed based on residual stress and roughness.