The optimization of mechanical property and corrosion resistance of WC-6Co cemented carbide by Mo2C content

Abstract

WC-6Co cemented carbide with super mechanical properties and excellent corrosion resistance was successfully prepared by optimizing Mo2C content. The structure, mechanical and anti-corrosion behaviors of cemented carbide were evaluated via a series of professional tests and measurements. The results revealed that the alloy phase of cemented carbide with various Mo2C contents was identical. Nevertheless, the content of Mo element in Co binder phase was higher than that in WC phase owing to the Mo2C dissolution in Co binder phase. The average grain size of WC displayed a downtrend after adding Mo2C additive. Differently, the Vickers hardness was increased after adding Mo2C additive and reached the maximum when the Mo2C content was 1.0%. In addition, the corrosion resistance of cemented carbide in 0.1 M HCl and NaOH solutions was improved by adding proper Mo2C additive. This was due to the synergistic effect of the optimized relative density, the modification of Co binder phase and the formation of passive film.