Investigation on integrity assessment tests of WRB metal-polymer-metal composites

Abstract

The warm roll bonding technique was adopted to fabricate Aluminum–polyurethane–Aluminum (Al–PU–Al) composites. Glass whiskers or SiC particles were added to reinforce the inner layer. The main objective of the present study is to examine experimentally the main manufacturing parameters, including interface properties and layer thicknesses, both of which control the strength and integrity of Al–PU–Al composites. For this purpose, three different tests were performed, namely the peel test, the single lap shear test, and the small punch test (SPT). A numerical study was carried out to study the effect of each parameter on the bond, the mechanical behaviors, and fracture behaviors of Al–PU–Al composites using the extended finite element method. The present results indicate that there is a critical diameter of the unbonded circle (D) beyond which the interlayer bonding strength decreases markedly for both the peel and the single lap shear tests. The critical value of D/W equals 0.2 for the peel test and 0.3 for the single lap shear test, where W is the plate width. There is no clear relation between the interlayer bonding strength measured, either from the peel test, or the single lap shear test, and the ultimate load measured from SPT. The mechanical behavior of Al–PU–Al composites measured from SPT is marginally affected by the interfacial bonding strength between the layers. The presence of clearance (0.1 mm) between the SPT specimen and the fixture decreased its ultimate load by about 10% for the bonded specimen, and 30% for the unbonded specimen.