Ideal tensile strength and shear strength of ZrO2(111)/Ni(111) ceramic-metal Interface: A first principle study

Abstract

The ideal mechanical strengths of ZrO2(111)/Ni(111) ceramic-metal (C-M) interface are calculated through simulated tensile and shear deformations using the first principles calculations. The structures of ZrO2(111)/Ni(111) interfaces with 1- and 3-layer Ni thicknesses are optimized and the mechanical properties are investigated. For tensile deformation in [111] direction, the Young's moduli of the 1-layer Ni and 3-layer Ni M-C models are 139.9GPa and 60.2GPa, respectively; and ultimate tensile strengths are 11.6GPa and 7.9GPa, respectively. For shear deformation in {111} 〈110〉 system, the shear moduli of the 1-layer Ni and 3-layer Ni M-C models are 43.9GPa and 30.4GPa, respectively; and ultimate shear strengths are 7.0GPa and 3.0GPa, respectively. For shear deformation in {111} 〈112−〉 system, the shear moduli of the 1-layer Ni and 3-layer Ni M-C models are 30.9GPa and 17.3GPa, respectively; and ultimate shear strengths are 6.0GPa and 1.8GPa, respectively. Overall, 1-layer Ni C-M interface models have better mechanical properties than those of 3-layer models. The observed strengths are explained by using charge distribution, electron localization function, and Bader charge transfer analyses. The results are important for designing robust thermal barrier coating through optimizing bond coat thickness.