The trapping of H in Σ = 5 (310)[001] symmetrical grain boundaries was studied by performing computer simulations at the atomic scale. The effect of Mg segregation was investigated at absolute zero by performing calculations on 3 grain boundary structures. These were a pure Al core structure, a Mg-segregated boundary and a precipitated boundary. The H-Mg affinity was found to be of second-order with respect to the core effect. The segregation of 10ppm of H at 300K was also investigated by means of Monte Carlo simulation. An H-induced core-structure change was found which could affect intergranular stress-corrosion cracking.

Intergranular Hydrogen Trapping in Al-Mg - a Monte Carlo Simulation. D.Tanguy, T.Magnin: Materials Science Forum, 2000, 331-337, 1601-6