Performance evaluation of D-gun sprayed WC-10Co-4Cr thin film on CF8M steel under scratch loading

Purpose WC-10Co-4Cr coatings are widely used to improve the surface durability of steel components, particularly in environments where wear resistance is critical. To better understand their performance, this study aims to examine how these coatings respond to mechanical loading in the form of scratch testing. Design/methodology/approach The coatings were applied to CF8M stainless steel using the detonation gun (D-Gun) technique. Both coated and uncoated samples were subjected to scratch tests under continuous load of 20 N, 50 N, 100 N 150 N, 200 N and ramp loading (20–200 N) conditions. Subsequently, microstructural characterization and phase analyses were carried out to identify features influencing the scratch response. Findings In scratch test, the coated surfaces showed the signs of localized plastic deformation with higher coefficient of friction as 0.247. In contrast, uncoated CF8M steel exhibited a lower coefficient of friction. The average apparent scratch hardness of both coated and uncoated steel was observed as 8.70 GPa and 7.4 GPa, respectively. Apparent scratch hardness measurements indicated the coating significantly enhanced hardness, with brittle microstructure. Originality/value The findings suggest that both the internal structure and phase composition of the coating play a crucial role in its mechanical behavior. This study enhances our understanding of the performance of thermally sprayed WC-based coatings under scratch loading and underscores key considerations for their application in wear-sensitive environments.