A novel hybrid ultrasonic and electromagnetic field assisted laser cladding: Experimental study and synergistic effects

In this paper, a novel hybrid ultrasonic and electromagnetic (UEM) field-assisted laser cladding (LC) is proposed, and the synergistic effect between ultrasonic and electromagnetic fields in the molten pool is investigated. The experimental investigation is conducted on the impact of hybrid UEM fields on the defects (i.e. pores and cracks), surface roughness, microstructure evolution and mechanical properties of Inconel 718 coating. It is indicated that hybrid UEM fields effectively reduces the cladding layer defects and flattens the surface of the coating, promotes the columnar to equiaxed transition (CET) and produces the cellular sub-grains inside the existed grains. In addition, hybrid UEM field increases the coating microhardness and improves the wear performance of the coating. Overall, this study shows that the hybrid UEM field has the potential to manufacture practically the metallic component with high quality in the directed energy deposition field. • Hybrid UEM reduces the cladded layer pores and cracks significantly. • The hybrid UEM refines the grains, improves the CET and the sub-grains formation. • Under hybrid UEM, the layer surface exhibits relatively smooth. • The ultrasonic induced cavitation effect can be intensified by the Lorentz force. • The coating properties increase significantly with hybrid UEM field.