Improving nucleation rate of in-situ synthesized WC by pre-adding ZrC as nucleating agent

To address the low nucleation rate of in-situ synthesized WC, ZrC was used as the nucleating agent in this study and its effectiveness was investigated by first-principles calculations and experimental methods. The results demonstrate that the W-terminated WC(0001)/C-terminated ZrC(111) interface exhibits the highest adhesion work (8.06 J m⁻²) and the lowest interfacial energy (2.61–2.68 J m⁻²) due to the formation of mixed covalent and ionic bonds between W and C atoms at the interface, making it more likely to become a potential heterogeneous nucleation interface for WC since the adsorption of W atoms on the C-terminated ZrC (111) surface for nucleation can significantly reduce its nucleation work. The experimental results confirm that ZrC is an effective nucleating agent to promote the nucleation of WC. The number and content of in-situ synthesized WC particles in the composite coating with 1.5 wt% ZrC added are 159.2 % and 141.8 % of those in the composite coating without nucleating agent added, respectively.