Effect of an aggressive medium on discontinuous deformation of aluminum–magnesium alloy AlMg6

It is experimentally shown that the molecular (chemical) process of surface etching of deformed aluminum–magnesium alloy AlMg6 causes the development of a macroscopic plastic strain step with an amplitude of a few percent. Using numerical simulation of the polycrystalline solid etching process, it is shown that the corrosion front morphology varies during etching from Euclid (flat) to fractal (rough). The results obtained show the key role of the surface state on the development of macroscopic mechanical instability of a material exhibiting the Portevin–Le Chatelier effect.