Microstructure evolution and properties of in-situ ceramic particles reinforced Fe-based composite coating produced by ultrasonic vibration assisted laser cladding processing

Ultrasonic vibration assisted laser cladding processing was employed to fabricate ceramic particles reinforced Fe-based composite coatings. The influence of the ultrasonic vibration on the dilution, profile appearance, microstructure characteristics, and high temperature oxidation resistance of the composite coatings were investigated. Experimental results revealed that the profile roughness of the coatings was reduced by ultrasonic vibration during laser cladding processing, but the dilution of the coating was slightly increased. The heat and mass transfer in laser molten pool was improved by the ultrasonic vibration, resulting in the refining of the microstructure and increasing the amount of ceramics, as well as homogenizing the distribution of ceramics. The composite coating produced by 300 W ultrasonic vibration assisted laser cladding processing not only possessed good wear resistance, but also had high oxidation resistance. However, excessive ultrasonic vibration power increased the tendency of cracks in the coating.