Abstract
Automotive, aerospace, and energy applications demand for reliable coating systems to enhance the operating efficiency and the lifetime of processes, machines, and components. HVOF sprayed WC-CoCr coatings are commonly used, especially for wear resistant applications. Due to their high hardness and adapted corrosion resistance WC-CoCr coatings show perfect preconditions for highly stressed tribological systems. However, dynamic loads, caused by vibrations, alternating temperatures or cycling are challenging issues. Fatigue cracking and delamination can occur, resulting in fatal damage of the coated component. Therefore, crack and fatigue resistant high performance coatings are needed. In this research work, the influence of the substrate pre- and post-treatment (grit-blasting and micro-finishing) on the fatigue behavior of warm sprayed WC-CoCr is investigated. It was determined that the fatigue behavior of the applied coating can be improved by micro-finishing. The smooth surface structure results in a low interface roughness. This significantly reduces notching effects under load and enhances the fatigue strength of the specimen.
