Microstructure and wear mechanism of different laser-clad zones of Ti-based composite coating with high content of WC particles

Purpose This study aims to fabricate engineering-applicable coatings with high WC content via multitrack laser cladding to enhance the wear resistance of titanium alloys, characterize its microstructure, and explore the wear mechanisms between overlap and non-overlap zones. Design/methodology/approach The coating microstructural characteristics were investigated by X-ray diffraction, scanning electron microscopy coupled with energy-dispersive spectroscopy, electron backscatter diffraction. The wear behaviors of different laser-clad zones were studied using a 3D profilometer and X-ray photoelectron spectroscopy. Findings A W2C/W/TiC metallurgical bonding layer was formed between the WCp and Ti-matrix. High hardness W-rich phase, TiC mainly enhances the hardness of the Ti-matrix. Non-overlap zone’s high WCp content (54%) creates support and improves wear resistance, its wear mechanism is fatigue and abrasive wear. Serve three-bady abrasive wear occurs in the Ti-matrix of overlap zone, but the oxidation wear products reduce the coefficient of friction. The overlap zone’s wear mechanism is dominated by three-body abrasive wear and supplemented by oxidative wear and adhesive wear. Originality/value Leveraging the inherent WC distribution difference in overlap coatings, the strengthening and wear mechanisms of Ti-matrix after C/W solid-solution were investigated specifically. It supplements the engineering application of high-addition multitrack WC-reinforced Ti-based composite coatings by analyzing the differences and mechanisms of wear performance across various cladding zones, highlighting the necessity of improving WC distribution uniformity, and providing data support for wear failure analysis of such coatings.