Degradation of metal–polymer composite submitted to uniaxial deformations in 3.5% NaCl solution

Abstract

This research evaluated the degradation performance of metal–polymer laminates. The material employed was an electrolytic chromium-coated steel (ECCS) sheet, protected by polyethylene teraphthalate (PET). This composite was submitted to uniaxial deformations simulating those occurring in the formation of containers. Later, it was electrochemically tested in 3.5% NaCl w/v solution and characterised by scanning electron microscope (SEM). Finally, an evaluation of the degradation activity was made to determine the potential performance of the composite in canning applications. The results indicated that the deformation–degradation correlations of the layers depended on the plastic deformation, strain energy, surface quality of the PET polymer free from defects (with respect to a control sample), lack of continuity of the chromium oxide layer at the interface level due to the generation of microcracks, grain deformation in the metallic layers – both of ECCS and chromium layer – due to the generation of Lüder’s bands, loss of adherence detected by electrochemical tests and surface morphological changes of the protective polymer by uniaxial deformations.