Assessing the role of spray torch configuration and binder composition on high-temperature tribological characteristics of HVAF sprayed Cr3C2-based coatings

The durability of industrial components exposed to high temperatures can be increased through the deposition of high-velocity thermal sprayed Cr₃C₂-based coatings. The severity of material degradation varies according to operational requirements, for which an appropriate torch configuration and material composition are critical. The uniform embedding of wear-resistant Cr₃C₂ within an oxidation-resistant binder matrix allows high velocity air fuel (HVAF)-sprayed Cr₃C₂-based coatings to be widely used in high-temperature environments. However, consolidating these coatings demands an optimum particle velocity and temperature combination, primarily dependent on the spray torch design. Understanding the role of spray torch variants with various combustion chamber and accelerating zone designs is essential, which might influence the coating formation mechanism. Accordingly, Cr₃C₂-25NiCr and Cr₃C₂-30NiCrMoNb were sprayed using different HVAF torches (AK 06/05: generates different energy (thermal + kinetic) output) to understand the role of the binder as well as the torch design. Splat studies will be conducted to understand the coating formation and correlate with the microstructural characteristics of Cr₃C₂-based coatings. Subsequently, a detailed performance evaluation will be performed through high-temperature erosion and sliding wear. The above comprehensive evaluation enables a detailed techno-commercial feasibility assessment of the HVAF spray technique for industrial exploitation in different applications.