Laser cladding Co-based coating coupled with electromagnetic/ultrasonic compound energy field

Abstract

Co-based coatings were fabricated by laser cladding coupled with electromagnetic/ultrasonic compound energy field. The microstructural evolution and wear resistance were investigated. The experiment results indicate that the number of coarse dendrites is continuously reduced and that of fine grains is gradually increased as the energy field changes from single to compound energy field. The compound energy field makes the cladding layer microstructure more uniform and refined, leading to the cladding layer showing the best wear resistance, in terms of highest microhardness (531.95 Hv_0.2), lowest friction coefficient (0.259), minimum wear rate (8.96 × 10⁻²mm³ (Nm)⁻¹). The solidification structure of cladding layer can be effectively controlled by applying an external physical field in the process of laser cladding with obvious improvements in mechanical properties, especially for the compound energy field.