Microstructure, wear property and oxidation performance of cemented carbides doped with the different additives

To enhance the oxidation-wear capacity of cemented carbides, WC-Co(Re,Ru,NbC) cermets were prepared and researched. The Nb segregation was detected in WC-10Co-3NbC. A good oxidation resistance of Co phase contributed to improving the oxidation performance of WC phase and further enhancing the oxidation-wear properties of cermets. WC-10Co containing Re and Ru presented a relatively better oxidation-wear performance. The strength mechanisms of Re and Ru dissolved into Co were revealed by first principles calculation and microstructure characterization. In comparison to pure Co, Co-Re and Co-Ru showed the higher adsorption energy to oxygen corresponding to -0.384 and - 0.378 eV/atom respectively. In addition, the diffusion energy barrier of oxygen atom for Co-Re (5.02 eV) was higher than that for Co-Ru (4.43 eV). Whereas, WC-10Co-3Re presented the worse oxidation resistance than WC-10Co-3Ru during the oxidation experiment. A likely explanation for this involved the fact that the oxidation film for WC-10Co-3Re showed more pores and the looser film promoted the oxidation process.