The formation of atomic and sub-nano scale pores under tensile strain in oxide films on Zr alloys: A first-principles study

The corrosion resistance of Zr alloys tightly connects to the oxide films on Zr alloys. We use first-principles computational tensile test to perform a systematical investigation on the tensile strain-stress behaviors of monoclinic zirconia, and reveal the formation mechanism of initial pores and cracks in the oxide films. Based on calculated results, we propose a new mechanism of initiation of pores in the oxide films, which has solved the puzzle of pore formation at oxide/metal (O/M) interface of pure Zr. Moreover, our results are also well consistent with many previous microstructure characterization results of Zr alloys.