Hydrogen Permeation and Diffusion in Beryllium

A precise hydrogen permeation experiment for beryllium was conducted at a temperature ranging from 735 to 1000 K under hydrogen gas pressure of 10¹ to 10³ Pa. Diffusion coefficient and permeation coefficient were determined from the steady state penneation and time transient penneation independently. The steady state penneation rate was proportional to the square root of H₂ pressure and the time sequence of penneation rate agreed well with theoretical one, indicating that the penneation controlled by bulk diffusion. The temperature dependencies of the penneation coefficients (Φ) and diffusion coefficients (D) were respectively,Φ=(1.0±0.1)×10⁻⁶exp[−73±20(kJ/mol)/RT]  (mol·m⁻¹·s⁻¹·Pa^1/2),D=(1.3±0.1)×10⁻⁷exp[59±20(kJ/mol)/RT] (m²·s⁻¹).Solubility calculated from the relation Φ=DS wasS=7.1 exp[−14(kJ/mol)/RT] (mol·m⁻³·Pa^−1/2).