An ab initio simulation on electron beam physical vapor deposition of Gd2Zr2O7 coating by density functional theory and kinetic Monte Carlo

Abstract

AbstractWithout any experimental inputs, the electron beam physical vapor deposition (EB‐PVD) of Gd2Zr2O7 with much potential for thermal barrier coatings was investigated by use of the kinetic Monte Carlo, after fitting the potential function using lattice inversion method and “coarse‐grained” mapping on the cohesive energy calculated by density functional theory, to reveal the effect of critical processing parameters of EB‐PVD on the microstructures and porosity of the deposited coating, for example, substrate temperature, deposition rate and incident angle. Based on the lower energy barrier calculated by a nudged elastic band, intra‐layer diffusion is easier than interlayer diffusion, attributed to the fewer bonds in the former. Furthermore, the porosity of the coating decreases with the increase of temperature or decrease of deposition rate, with the gradual disappearing large gaps among columnar crystals and filled pores, because of the increase of transition probability and transition times. With the decreasing incident angle, the area of the shadow zone decreases and less particles can be blocked by previously deposited ones, making the columnar crystals disappear gradually, with more like laminated structures.