Revealing the interface characteristic of the semi-coherent Co(111)/WC(0001) interface: a first principles investigation

In the present work, based on the first-principles calculations, we systematically discuss the electronic structure, adhesion work, interface energy, chemical bonding strength and interfacial mechanical failure forms of semi-coherent Co(111)/WC(0001) interface. After relaxation, the interface configurations of the middle top (MT) sites migrate toward the hexagonal close-packed hollow top sites (HCP), indicating that the MT occupancy is unstable. The atoms at the interface are more inclined to the HCP sites. The calculated results indicate that the C-terminated HCP1 site interface configuration has the largest adhesion work and the smallest interface energy, which depends on the formation of strong C-Co covalent bonds at the interface. Finally, the strong Co/WC interface configuration formed in the WC-Co composites can effectively carry out load transfer and reduce stress concentration, improving the strength and plasticity of the composites.