Ultrasonic-Induced Grain Refinement in Laser Cladding Nickel-Based Superalloy Reinforced by WC Particles

Laser cladding was used to prepare three composite coatings, i.e., Inconel 718 nickel-based superalloy (IN718), IN718-50 wt.% WC created by adding tungsten carbide (WC) particles and assisted ultrasonic vibration. The phase composition, microstructure evolution, microhardness, residual stress tribological properties of the coatings were studied. addition enhances hardness improves properties, but also causes aggregation considerable formation carbides associated with rough structure. Ultrasonic vibration greatly refines solidification microstructure, as it can break growing dendrites, reduce reinforced refine solidified average microhardness latter two increased 36.37% 57.15%, respectively, compared first IN718 coating, last coating (ultrasonic assistance) had lowest COF (0.494). refined converted wear mechanism from adhesive abrasive wear. In addition, resultant on surface roughly doubled after 50 WC, only 49.53% treatment. simulation results indicate that acoustic cavitation mainly occurs in middle bottom molten pool proper frequency is conducive generation effect.