Adhesion, bonding and tensile properties of Ti doped WC (001)/diamond (111) interface: A first-principles calculation

Abstract

It is still a challenge to deposit a highly adhering diamond film on the WC-based cemented carbide. Here, we doped Ti into the WC/diamond interfaces to improve the adhesion and investigated the influences of Ti doping on adhesion work, electronic properties and tensile strength of WC (001)/diamond (111) interfaces by using first-principles calculations. The results show that the adhesion work of the C-terminated WC/diamond interface is higher than that of the W-terminated WC/diamond interface. By comparing with the adhesion work at the clean interface, it is shown that Ti-doped interface can lead to a significant improvement in the bonding strength. Besides, the electronic structure indicates that the Ti atom transfers electrons not only to the diamond side but also to the WC side, thus enhancing the charge transfer at the interface. Furthermore, the tensile simulation tests show that the maximum tensile stress increases by 13.46% with no change in the fracture elongation for the W-terminated interface after Ti doping. The maximum tensile stress increases slightly, but the fracture elongation increases by 2% for the C-terminated interface after Ti doping. As a result, this can provide theoretical guidance for the interface modification of WC-based carbide and diamond by doping Ti.