Failure and fracture micro-mechanisms in metal-composite single lap joints produced by welding-based joining techniques. (February 2016)

• Record Type: Journal Article
• Authors: Goushegir, S.M.; dos Santos, J.F.; Amancio-Filho, S.T.
• Is Part Of: Composites. Volume 81(2016)
• Page Start: 121
• Page End: 128
• Publication Date: 2016-02
• Subjects: A. Polymer-matrix composites (PMCs) -- B. Fracture -- D. Fractography -- E. Joints/joining; Composite materials -- Periodicals; Manufacturing processes -- Periodicals; Composite materials; Manufacturing processes; Periodicals; 620.11805
• DOI: 10.1016/j.compositesa.2015.11.001
• Languages: English
• ISSNs: 1359-835X

Abstract

Abstract: Welding-based joining technologies have been recently developed for metal-composite lightweight structures. In this work, the welding-based joining technology, friction spot joining, was selected to study the failure and fracture micro-mechanisms of an aluminum-composite single lap joint. Failure analysis suggested that the radial cracks nucleate at the periphery of the bonding area and propagate rapidly until failure of the so-called adhesion zone. Upon further loading the cracks propagate into the transition and plastically deformed zones leading to a reduction of the stiffness of the joint. The findings of the fractography demonstrated a mixed brittle-ductile fracture. Three zones were identified on the fracture surfaces: a smooth and featureless area demonstrating brittle fracture, a quasi-smooth area representing a mixture of ductile and brittle fractures and finally a zone with a highly rough surface implying ductile fracture of the composite part. Further, fiber pull-out and breakage were identified as additional fracture micro-mechanisms.