Effects of Ti/Nb Dual-Element Addition on the Microstructure and Properties of Tungsten Carbide-Reinforced Laser Cladding Coatings

Abstract

Metal-ceramic composite coatings are produced on the surface of equipment components by laser cladding, improving the abrasive wear resistance of components and extending their service life. However, defects such as brittleness and cracks limit the wide application of metal-ceramic clad coatings in the field of construction machinery. In the present study, a dual-element (Ti/Nb) alloying method is innovatively adopted to regulate the microstructure and mechanical properties of tungsten carbide (WC)-reinforced clad coatings. Experimental results show that with the introduction of Ti/Nb, novel reinforcements are in-situ synthesized in the cladding coatings with two different kinds of morphologies: one is a core-shell carbide with the core of pure TiC and a shell of (Ti,Nb,W)C multiple carbide; the other is a (Ti,Nb,W)C multiple carbide. With 8 wt.% Ti/Nb addition, the newly formed multiple carbides with the appropriate content are well-dispersed and distributed in the clad coating, which effectively transfers load, inhibits the initiation and expansion of micro-cracks, and resists the wear damage of hard abrasive particles, solving the technical problems of the simultaneous improvement of toughness and abrasive wear resistance of metal-ceramic laser cladding coatings.