Adhesive sliding and interfacial property of YAlO3/TiC interface: A first principles investigation

Abstract With consideration about the different termination conditions of atomic layer, six kinds of YAlO3(001)/TiC(100) coherent interface models were selectively constructed based on the results of lattice mismatch calculation and surface convergence test. The work of adhesion and interfacial energy were calculated by first principles method, which is used to analyze their interface adhesive strength and stability to find out interface structures with excellent property. Charge density difference and electron localization functions were calculated to analyze interfacial atomic bonding characteristics. The YAlO3(001)/TiC(100) interfacial structure with the best grain boundary crack and displacement resistance were predicted by the adhesive sliding simulation and potential barrier calculation of preferable formed interfacial structures. The calculation results show that the lattice mismatch of YAlO3(001)/TiC(100) interfacial structures is very small, about 2.5%, which indicates they have the advantage of forming coherent interfaces. The work of adhesion of O1-Ti interface is the largest (Wad = 5.74 J/m2), which is followed by that of the O1-C interface (Wad = 5.73 J/m2). Their interface structures are similar and interfacial atomic bond type are both mixture of covalent bond (between O atom and C atom) and ionic bond (between O atom and Ti atom). However, the interfacial energy of O1-C is the smallest (γ = 2.16 J/m2), which reveals that the O1-C type YAlO3(001)/TiC(100) interface is the most stable. In addition, the sliding direction static friction force of O1-C model is 1.24 times larger than that of O1-Ti, and most of the O1-C interfacial barrier is larger than that of O1-Ti structure in a sliding period. Therefore, it can be predicted that a YAlO3(001)/TiC(100) interface with excellent combination property will be preferable formed in type of O1-C structure. The densification and mechanical property are expected to be greatly improved in TiC reinforced wear-resistance coating and other functional ceramics after adding YAlO3 additive.