An atomistic investigation into the nature of fracture of Ni/Al2O3 interface with yttrium dopant under tension

This study performs a first principle study of Ni(1 1 1)/α-Al2O3(0 0 0 1) interface with yttrium dopant, and aims to understand the interfacial fracture behavior of a thermal barrier coating at atomic level. Uniaxial tensile simulations by density functional theory approach are conducted for a stable configuration of this interface, and its theoretical tensile strength and work of separation are extracted. By observing the variations of the atomic bonds and valence charge densities near interface region, we conclude that the Y doped Ni/Al2O3 interface breaks along the Y-Al and Y-O atomic bonds, tends to fracture in a ductile way.