Effect of magnetic-electric-ultrasonic fields on microstructure and properties of Ni60A laser cladding coating

•The number of cracks in coating is reduced significantly with MPF.•The grains are refined and the coating microhardness is increased by the MPF.•The mechanical properties and corrosive resistance of coating are improved significantly with MPF. Ni60 coating is prepared utilizing laser cladding on 45 steel assisted by magnetic-ultrasonic-electric field. The effect of multi-physical fields on the cracking tendency, microstructure, phase composition, mechanical properties and corrosive resistance of coating is investigated. As results indicate, the macro-morphology of coating is affected by the multi-physical field and the microstructure is refined, which uniformizes the element distribution and prominently optimizes the tribological and anti-corrosive performance of coating, the number of cracks in the coating under multi-physical field reduce by 76.92%, compared with that without physical field, the average microhardness increases by 37.89%, the average friction coefficient decreases by 61.96%, the average wear loss decreases by 61.05%, the corrosive rate decreases by 93.01%.