First Principles Investigation Of The Effect Of Zr(Cr_1-xFe_x)₂ Precipitation On Hydrogen Absorption Properties Of Zirconium Alloys

Zirconium alloys are used as the fuel cladding materials in water-cooled nuclear power reactors.Corrosion and hydrogen uptake are two important issues in the application of zirconium alloys,which involves the lifetime of fuel assembles,and the safety and reliability of the operation for nuclear power reactors.Hence,how to improve the corrosion resistance and reduce the amount of hydrogen uptake of the fuel cladding for high burn-up of fuel assemblies need to be further investigation.Density functional theory has been an important tool in the electronic properties on the condensed matter systems.In the recent decades,the study on hydrogen in metals or other solids with the first principles based on density functional theory has been widely put into application.In this paper,the formation energies and diffusion energies of hydrogen in Zr(Cr_1-x-x Fe_x)₂?x=0.125⁰.875?precipitation are studied by first principles method based on density functional theory.We also calculated the formation energies and diffusion energies of hydrogen in?-Zr for comparison.The results show that,?1?The formation energy of a hydrogen in Zr(Cr_1-x-x Fe_x)₂ precipitation decreases with the increase of Cr/Fe atom ratio,it suggests that the Zr(Cr_1-xFe_x)₂ precipitation with higher Cr/Fe ratio is energetic favorable for the hydrogen.?2??-Zr is a more energetic favorable place for the hydrogen than the Zr(Cr_1-x-x Fe_x)₂ precipitation,because the hydrogen interstitial formation energy in?-Zr is lower than that in the Zr(Cr_1-x-x Fe_x)₂ precipitation.?3?The diffusion energies of hydrogen in Zr(Cr_1-x-x Fe_x)₂ precipitation are between 0.12 eV and0.35 eV,and the diffusion energies of hydrogen in?-Zr are 0.43 eV.So hydrogen is easier to diffuse in Zr(Cr_1-xFe_x)₂ precipitation than it in?-Zr.