Microstructural and Tribo-mechanical Properties of Arc-Sprayed CoCr-Based Coatings

Abstract Due to their superior wear and oxidation resistance, Stellite™ coatings are widely used in industrial applications, where the exposed high temperature. Common processes for applying include high-velocity oxy-fuel spraying, laser cladding, plasma transferred arc welding. Although welding consumables or similar form of cored wires (CoCr base without property rights) commercially available, there hardly any studies on arc-sprayed available literature. In this study, microstructural characteristics deposits were investigated, which produced using a CoCr-based wire with addition 4.5 wt.% tungsten. The examined its as-sprayed state as well after elevated temperatures. microstructure was scrutinized by means electron microscopy, energy-dispersive x-ray spectroscopy, diffraction analyses synchrotron radiation. Tribo-mechanical tests conducted order assess performance coating. findings discussed compared those obtained from conventional coatings. It found that coating is predominantly composed Co-rich, Cr-rich lamellae comprising Co(Cr)-rich solid solution interspersed various oxides between individual lamellae. Solid hardening serves dominant strengthening mechanism, while precipitation effects evident. With regard behaviour, mainly contains CoCr 2 O 4 traces Co 3 . For heating above 550 °C, surface additionally consists Fe dry sliding experiments, shows decreased resistance processed HVOF PTA, whereas coefficient friction (COF) against alumina COF observed HVOF-sprayed coating, but lower than hardfacing alloy deposited PTA.