Cohesion and tensile properties of W-TiC interface under irradiation

Highlights: • The formation of the W-TiC interface could increase the tensile strength of W. • The W-W bond is weaker and stronger than the W-C and Ti-C bonds in the interface area. • Irradiation reduces cohesion strength, interface stability, and tensile strength of the W-TiC interface. • TiC could increase and decrease the tensile strength of W after irradiation along the directions parallel and perpendicular to the interface, respectively. • Present results agree well with experimental observations in the literature. -- Abstract: First principles calculation reveals that the formation of the TiC(001)/W(001) interface could increase the tensile strength of W, which is due to the stronger W-W bond in the interface than that in W bulk. Interestingly, the descending sequence of the bonding strength of the bonds in the interface is as follows: W-C → W-W →Ti-C, and the Ti-C bond in the interface is weaker than that in TiC bulk. It is also found that irradiation has an important effect to reduce cohesion strength, interface stability, and tensile strength of the TiC(001)/W(001) interface, and that such an effect is mainly attributed to the debonding of the W-C and Ti-C bonds as a result of the formation of carbon clusters due to irradiation. Furthermore, the addition of TiC could improve the tensile strength of W after irradiation under tensile loading along the direction parallel to the interface, while decrease the tensile strength of irradiated W under tensile loading along the direction perpendicular to the interface.