Corrosion and corrosive wear behavior of WC-MgO composites with and without grain-growth inhibitors

This article reports our recent studies on WC-4.3 wt.%MgO composites with particular interest in effects of grain-growth inhibitors (VC and Cr3C2) on corrosion and corrosive wear behavior of the WC-MgO composites in acidic and alkaline solutions, respectively. It was demonstrated that the composites possessed higher corrosion resistances in the acidic solution than in the alkaline solution. Refining microstructure with the grain-growth inhibitors mechanically strengthened the WC-MgO composite and improved its corrosion resistance in the acid solution in which the material was passivated. While the situation was reversed when tested in the alkaline solution in which no passivation occurred. Such a variation in the corrosion behavior affected their performance during corrosive wear tests in the acidic and alkaline solutions. Possible mechanisms behind are discussed.