Stress in aluminum induced by hydrogen absorption during cathodic polarization

Hydrogen concentrations in metals during aqueous corrosion are influenced by absorption kinetics. In situ measurement of hydrogen-induced stress was used to characterize hydrogen absorption into aluminum thin films during cathodic polarization in sulfuric acid, in the presence of competing gas evolution. Absorption-induced compressive stress increased with decreasing potential, reaching levels indicating average H concentrations of 0.3 at.%. Dependences of stress on potential and scan rate suggested that rates of hydrogen desorption but not absorption were kinetically limited.