The exceptional wear resistance of cemented carbides, owing to the combination of a tough metal binder with a hard carbide, has resulted in their applications in many engineering fields. In addition to their high performance in mining and cutting tool applications, cemented carbides are increasingly used in a variety of other industrial applications, such as seal rings, linings, valves, jet nozzles, saw blades, fluid mixers and conveyor belt scrapers. These applications differ from the traditional uses in that significantly longer lifetimes are demanded and components may be expected to remain in service for several years. If components are not only subjected to wear processes but are also in contact with chemically aggressive environments, corrosion can play a major role in the degradation of the surface and can significantly accelerate wear. The corrosion behavior was investigated using the electrochemical polarization tests in 1 M sodium chloride and synthetic mine water solutions. Three types of corrosion tests were done on the samples by electrochemical techniques: Potential versus time test, Potentiodynamic Polarisation scans and Chronoamperometry. It was found that ruthenium affected the cathodic Tafel constant β_c in synthetic mine water, but not really in NaCI. It was also observed that the passivity range and corrosion resistance decreases in order of synthetic mine water> sodium chloride. It also appears that Ru is more effective in improving corrosion resistance than vanadium carbide. Ruthenium additions of up to 3 wt% Ru of the WC-10%Co alloy increased the corrosion resistance of the WC-Co alloys. This is attributed to the stabilization of the cobalt fcc phase due to ruthenium additions while hep phase is obtained after VC additions.
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