Effect of Copper on Microstructure and Performance of WC/NiAl/TiC Composite Coatings by Laser Cladding

Intermetallic compounds with special physical and chemical properties are considered to be advanced materials. However, the brittleness at room temperature of intermetallic compounds leads to poor performance, which limits its widespread application in engineering. The objective of this study is to investigate the strengthening mechanism of the copper (Cu) on the microstructure and material performance of WC/NiAl/TiC composite coatings by the laser cladding process. The results reveale that Cu element has a significant effect on the microstructure evolution of the coatings by inhibiting coarse crystal formation. The refined microstructure of the layer had been realized. X-ray diffraction (XRD) analysis demonstrate a reduction in lattice spacing within the composite coating structure as the proper Cu is added. Furthermore, the addition of Cu contributed to an enhancement in microhardness (868.9 HV0.2) and wear resistance. With 3% copper been added, the wear loss of the coatings has been reduced by 81.13% and the average microhardness value has been increased by 1.4 times as well. Moreover, the chemical metallurgical bond is produced between the particles and bonding phase resulting in strengthened compactness within the layer acting as a physical barrier-like film that increases polarization resistance. After preparing the NiAl composite cladding layer, it is found that the lattice spacing has significantly changed with the addition of Cu element. The formation of microcracks and coarse columnar crystals is suppressed, which contributes to achieving the microstructure refinement and the performance of the coating is improved to resist wear and corrosion.image (c) 2024 WILEY-VCH GmbH