Microstructure, interface, and nanostructured surface modifications to improve mechanical and tribological performance of electrodeposited Ni-W-TaC composite coating

Abstract In this study, the influence of codeposited TaC particles on the microstructure of Ni W matrix was investigated. The microstructure was significantly influenced, and a thick amorphous interface between TaC and the matrix phase was observed. Similarly, further advanced surface modification treatment, ultrasonic nanocrystal surface modification (UNSM) technique, was applied to the Ni-W-TaC composite coating to investigate surface characteristics, mechanical, and tribological performance. Different characterization tools such as XRD, HRTEM, SEM, EDS, and surface roughness tests have been utilized to examine the microstructure, interface, and surface-related properties of Ni W, Ni-W-TaC, and UNSM Ni-W-TaC composite coatings. The synergetic strength of TaC incorporation in the microstructure and nanostructured surface modification distinctly improved the microhardness (≈ 880 HV), with small indentation, of UNSM Ni-W-TaC coating. As a result, a reduction in the coefficient of friction (COF) (μ ≈ 0.1) under a 15 N load was obtained in UNSM Ni-W-TaC coating against a steel ball under dry lubrication conditions.