Microstructure and wear resistance of tungsten carbide particle reinforced titanium alloy coating by WAAM

A tungsten carbide particle reinforced Ti-6Al-3Nb-2Zr-1Mo alloy coating was prepared by wire arc additive manufacturing (WAAM) with wire-powder feeding simultaneously. The study shows that the titanium alloy matrix exists in the form of a metastable phase β-Ti, and the addition of tungsten carbide particles significantly refines its grains. Tungsten carbide particles retain a spherical shape, with only the surface undergoing dissolution and releasing W and C atoms. The results of the dry sliding friction test reveal the superior wear resistance of the composite coating, primarily attributed to the shadow effect of the tungsten carbide particles, the enhanced hardness, and the formation of a self-lubricating oxide layer.