Influence of vibrations on interface delamination in metal–polymer composites

Abstract

The main objective of this work was the study of vibration effects on the viscoelastic coating protecting the steel layer in a metal–polymer composite, with simulated conditions of the transportation of food containers. Mechanical resonance tests in metal–polymer [electrolytic chromium‐coated steel–poly(ethylene terephthalate) (PET)] sheets were performed to generate vibration conditions to induce structural modifications in the viscoelastic layer covering the surface of the plates. Consequently, schematic representations of the areas affected by these modifications were made. The modified structures were later analyzed by electron microscopy to detect and evaluate alterations in the morphology of the material. In addition, vibrational Raman spectroscopy analyses were performed to assess the chemical and structural changes on the protective PET at the metal–polymer interface level. The results of this study are expected to provide basic information on the mechanisms and nature of the delamination processes taking place in metal–polymer laminates employed in food‐container applications. These damages have previously been detected in some food containers made of PET materials. The study of these damages can lead to the improvement of current composites or the development of higher quality materials. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Evaluation of NaCl Effect on Vibration-Delaminated Metal-Polymer Composites by Improved Micro-Raman Methodology

“…Figure 3 shows the presence of delamination defects caused by the vibration tests, favoring the physicochemical interactions with NaCl at the metal-polymer interface. Since this work employed samples with vibration-induced delamination defects or antinodes [13], it is important to mention that such delaminations were the result of fractures and deformations of the Cr 2 O 3 layer at localized points, breaking up the PET-polymer/chromium-layer chemical bonds. e above is corroborated by SEM images, where the activity of the electrolyte was more intense in the darker areas, corresponding to polymer detachment zones.…”

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

“…However, the originality of the present study was to experimentally demonstrate that not always there is a linear effect resulting from uniaxial deformations and much less in a saline medium; it has been significant only for the 25% deformation strain. The changes in the potential and net charge transferred demonstrated variable behaviours for the 5-25% deformation range (Figures 4 and 5), due to the microstructural complexity of the composite, and the anodic and cathodic mechanisms involved [13,14]. That is, the deformations mainly affected areas of the chromium layers on steel; an assumption made because of the observable marks on the PET polymer caused by the morphological changes of the layers; it is evident that such layers crack and fracture (Figures 8, 10 and 11) in thin sheets under very aggressive environments (3.5% NaCl) and show discontinuities in certain areas, allowing low-deformation changes to exhibit increased activity in the layers.…”

“…The axially deformed samples (5-25%) were electrochemically tested and characterised; when observing their morphological changes (especially at extreme deformation), they showed evidences of degradation in the electrolytic chromium and PET polymer layers by the electrochemical activity of the saline solution [13,14].…”

Numerical Investigations on GFRP beam with Delaminations

“…Pushparajet aldid research on the vibration Analysis of laminated composite structures using numerical method to figure out the vibration parameters of a Glass fibre Reinforced Polymer Composite and Carbon Fibre Reinforced Polymer Composite (6).E.Zumelzu et al did study of vibrationalparameters on the viscoelastic coating on the steel layer of a metal -polymer composite, with replicatedsituation of the moving of food containers (7). Sharayuet al studied about the consequence of delamination on vibration parameters of composite structure to arrive mode shapes and modal frequencies at different location of delaminations (8).…”