New Method to Distinguish Adhesion and Cohesion Stresses in Metal/Polymer Composites

Marcos Vinicius Utumi,Alexandre Luís Gasparin,Leandro Luís Corso

doi:10.1590/1980-5373-mr-2020-0277

Abstract

Abstract This study aims at presenting a new analysis method for adhesive (interfacial) and cohesive (bulk) failures in aluminum (Al) and high-density polyethylene (HDPE) sandwich composites. The samples were submitted to tensile strength tests, according to ASTM C297 so as to obtain the pull-off stresses. The delaminated aluminum surfaces were analyzed with SEM/EDS (Scanning Electronic Microscopy with Energy Dispersive Scanning). The images were calculated using a genetic algorithm (GA), where the areas with cohesive and adhesive failures were identified by the presence or absence of organic compounds. The proposed method also uses the data from the pull-off tests to determine the stress values of adhesion and cohesion separately. Applying the new method, the mean stress of cohesion was 4.17 MPa, and for adhesion it was 0.57 MPa. Thus, it was possible to distinguish and calculate the failure stresses applied to metal/polymer composites.

Highlights

The manufacturing process of an aluminum and polyethylene composite is used in several areas, from the food industry packaging to construction and auto industry revetments[1,2]
In pull-off tests for the composite tensile strength, the adhesive area varied from 16% up to 91%, and the maximum stress up to rupture from 0.89 up to 3.59 MPa
The maximum stress found in adhesive failure was 0.57 MPa and for the cohesive failure it was 4.17 MPa, using the genetic algorithm (GA)

Summary

Introduction

The manufacturing process of an aluminum and polyethylene composite is used in several areas, from the food industry packaging to construction and auto industry revetments[1,2]. Polymer matrix composites have attracted the interest of researchers and industries because the combination of those materials present better properties than those obtained with the materials used individually[3]. Natural fillers are an option extensively applied for the natural fiber-reinforced composites in the packaging industry as excellent mechanical supports with functional electrical and bio-material features[4,5,6]. It is important to register that the modification of surfaces and loads used for a composite can be adjusted with the results of adhesion properties, developing a more adequate material for the application[8]

Objectives

Methods

Results

Conclusion