Design and Performance Evaluation of Tungsten Carbide–Cobalt (WC–Co) Wear-Resistant Surfaces for Next-Generation Mechanical Components

Progressive surface degradation leads to increased friction, surface loss, energy consumption, and early failure in mechanical components subjected to repeated contact, abrasive and sliding situations. In many tribological situations, conventional metallic surfaces may not be able to provide enough wear resistance, and the interactions of coating composition and tribological parameters are insufficiently studied. The purpose of this study is to design, optimise and evaluate the characteristics of tungsten carbide–cobalt (WC–Co) wear resistant surfaces on the next-generation mechanical components, in order to recognise the optimal coating composition, its thickness and the possibility of adjusting the tribological operating conditions. Coatings with 10-20 wt.% Co content and 80-90 wt. % WC were investigated on alloy-steel substrates for coating thicknesses of 150 – 300 μm. The tribological behaviour was evaluated under a range of loads of 20–60 N, speeds of 0.2–0.8 m/s and distances of 3000 m. The weightages α = 0.35, β = 0.40, and γ = 0.25 were used for friction, wear, and hardness respectively using the multi-objective response surface optimisation. The optimised condition consisting of 88 wt. % WC, 12 wt. % Co with a thickness of 250 μm gave a result of 1320 HV, with its coefficient of friction being reduced from 0.58 to 0.34 and the specific wear rate decreased from 7.4 × 10⁻⁷ to 2.5 × 10⁻⁷ mm³/N·m. The surface roughness reduced from 1.85 μm to 0.92 μm and the predictive model's R² value was 0.94. The findings indicate that the optimised WC–Co surfaces can significantly improve the hardness, frictional behavior and wear resistance suggesting a plausible path for improving the service life of high contact mechanical components under challenging operating conditions.