%0 journal article
%@ 1359-835X
%A Goushegir, S.M., dos Santos, J.F., Amancio-Filho, S.T.

%D 2016
%J Composites / A

%P 121-128 
%R doi:10.1016/j.compositesa.2015.11.001
%T Failure and fracture micro-mechanisms in metal-composite single lap joints produced by welding-based joining techniques
%U https://doi.org/10.1016/j.compositesa.2015.11.001
 
%X 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.