Boundary layer of hydrogen concentration under plastic deformation

Abstract

A new model of instability of uniform plastic deformation with the formation of Lüders bands on the surface of a material being deformed is experimentally confirmed. It has been found that nonuniform plastic deformations correlate with hydrogen concentration during the testing of metal specimens in the atmosphere at room temperature. The presence of additional pores and microcracks formed as a result of plastic deformation is the cause of the correlation between plastic deformations and hydrogen concentrations in aluminum alloys. The effect of the boundary layer in the distribution of hydrogen concentrations has been detected. It reflects the fact that all changes associated with mechanical and thermo-mechanical loading are localized in a thin boundary layer at the surface of a metal specimen. The wave approach to the analysis of the continuum equations and the model of the boundary layer of a bicontinuous medium containing hydrogen are used to describe the observed phenomena. The constructed model makes it possible to describe the development of plastic deformation as a wave process in the boundary layer of a bicontinuous medium. Paris, 1923, vol. 176, pp. 507-510. 4. KeywordsPenning P. Mathematics of the Portevin-Le Chatelier effect. Acta Metallurgica, 1972, vol. 20, no. 10, pp. 1169-1175. DOI: 10.1016.Lebyodkin M., Brechetz Y., Estrin Y., Kubin L. Statistical behaviour and strain localization patterns in the Portevin-Le Chatelier effect. Acta Materialia, 1996, vol. 44, no. 11, pp. 4531-4541. DOI: 10.1016/135900076-6. 6.McCormiсk P.G. A model for the Portevin-Le Chatelier effect in substitutional alloys. Acta Metallurgica, 1972, vol. 20, no. 3, pp. 351-354. DOI: 10.1016 90028-4. 7.Kalk A., Nortmann A., Schwink C. Dynamic strain ageing and the boundaries of stable plastic deformation in Cu-Mn single crystals.