Investigation of novel nano-carbide WC/CoCr coatings applied by HVAF

Wear leads to high material and energy losses in various industries. The manufacturing of novel nano WC/Co powder feedstock materials promises a further increase in the performance of thermally sprayed wear protection coatings. These novel powders are thermally sprayed onto an S235 substrate by High Velocity Air Fuel (HVAF) spraying and the specimen are metallographically prepared and analyzed by means of light microscopy (LM), scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDX). Vickers Hardness testing is conducted by microindentation and the porosities are determined by optical image analysis. X-ray diffractometry (XRD) analysis are used to investigate the phase retention. Fine nanocrystalline WC-structures are preserved in the dense coatings. Coating properties as well as phase retention largely depend on the exact composition of the novel powders, i.e. decarburization and deposition efficiency vary, depending not only on the chemical composition but also on the powder manufacturing process materials. The resulting coatings exhibit high hardness values when compared to commercial submicron-WC references. The novel coating can contribute to reduced wear and therefore improve the efficient utilization of critical raw materials like tungsten.