W. Zorawski, N. Radek, Kielce University of Technology, Kielce, Poland

Summary: HVOF sprayed coatings are widely used to improve the service life of machine components. Influence of spraying parameters and different kinds of materials on coatings properties have been investigated in many works. Our investigations concern properties of HVOF sprayed two tungsten carbide coatings after applying electrical discharge machining (EDM) process. Applying tungsten carbide electrode enriched finished surfaces of sprayed coatings. The microstructure of the sprayed and EDM processed coatings were analysed with a scanning microscope JOEL JSM-5400, the element distribution with a microprobe ISIS 300 Oxford Instruments and phase composition by diffractometer D8 Advance (BRUKER). The roughness of coatings was measured with Talysurf-4, whereas Zwick 3210 was used to study their hardness. Well known dry abrasive rubber wheel tester and ball on disc tester were applied to estimate wear resistance and coefficient of friction.