Diffusion of Hydrogen in Aluminium

Abstract

To evaluate some of the interesting results from recent works on the precipitation of hydrogen in solid aluminium, it is needed to know the diffusivity of hydrogen in the metal, on which, however, there have been only two measurements with great inconsistency.Following Demarez et al. the diffusion coefficients of hydrogen in pure aluminium were determined over a temperature range of 570°∼630°C from the gas extraction curves obtained by the vacuum hot extraction method using cylindrical specimens, 1 cm in diameter and 1 cm in length.From the present result, the temperature dependence of diffusivity of hydrogen in aluminium can be written in a form D=2.0×10−2exp(−12000±1000⁄RT) cm2 sec−1.\ oindentThe activation energy obtained in the present experiment is in good agreement with that obtained by Eichenauer et al. over a temperature range of 470°∼590°C. The value of D0, however, is smaller by an order than that given by Eichenauer et al.