The H desorption properties of the pure Al and of the Al alloy were investigated by means of thermal desorption spectroscopy. In the case of the H thermal desorption spectrum, 2 peaks in the temperature were observed which were thought to correspond to desorption that was due to second-order surface reactions and diffusion. The activation energy for desorption, due to surface reaction, was equal to 38kJ/mol in the case of AA1050. In the case of AA1001, the activation energy and diffusion constant of H were calculated, by using a simple diffusion model, to be 50kJ/mol and 0.0005 to 0.0035cm2/s, respectively. The H which was desorbed from the Al alloy was estimated to be 0.159cm3 per 100g of Al. This was twice the equivalent value for AA1050.

Y.Hirohata, S.Fujimoto, T.Hino, T.Yamashina: Journal of Vacuum Science and Technology A, 1993, 11[5], 2637-41