Influence of TiC additions on the corrosion behaviour of WC–Co hardmetals in alkaline solution

•The TiC addition can improve the corrosion resistance of WC-Co in NaOH solution.•The existence of TiC can induce the formation of TiO2 nanofiliaments clusters.•The stable TiO2 can inhibit the dissolution of carbides grains in NaOH solution.

In this work, the effect of TiC additions on the corrosion behaviour of WC–10 wt.% Co hardmetals was investigated in a 1 mol/L NaOH solution. The results showed that the addition of TiC could make the open circuit potential (OCP) in the test solution more positive than the base alloy, lead to nobler free-corrosion potential value and decrease corrosion current density. The XRD results showed that the existence of TiC can inhibit the corrosion of carbide in hardmetals. Moreover, XPS and TEM results demonstrated that titanium dioxide formed in the surface films of the TiC content specimens in the NaOH solution.