materials Article Experimental and Finite Element Analysis of the Tensile Behavior of Architectured Cu-Al Composite Wires Alireza Dashti 1, * , Clément Keller 2 , Benoit Vieille 1 , Alain Guillet 1 and Christophe Bouvet 3   Citation: Dashti, A.; Keller, C.; Vieille, B.; Guillet, A.; Bouvet, C. Experimental and Finite Element Analysis of the Tensile Behavior of Architectured Cu-Al Composite Wires. Materials 2021, 14, 6305. https://doi.org/10.3390/ ma14216305 Academic Editor: Antonio Polimeni Received: 1 September 2021 Accepted: 19 October 2021 Published: 22 October 2021 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). 1 Groupe de Physique des Matériaux, UMR CNRS 6634, Normandie Université, Avenue de l’Université, 76800 Saint-Étienne-du-Rouvray, France; benoit.vieille@insa-rouen.fr (B.V.); alain.guillet@insa-rouen.fr (A.G.) 2 LGP—Laboratoire Génie de Production, ENIT—École Nationale d’Ingénieurs de Tarbes, 47 Av. d’Azereix, 65000 Tarbes, France; ckeller@enit.fr 3 IGMT, LMS Supaéro, BP 54032, CEDEX 4, 31055 Toulouse, France; christophe.bouvet@isae-supaero.fr * Correspondence: Alireza.dashti@insa-rouen.fr Abstract: The present study investigates, experimentally and numerically, the tensile behavior of copper-clad aluminum composite wires. Two fiber-matrix configurations, the conventional Al- core/Cu-case and a so-called architectured wire with a continuous copper network across the cross-section, were considered. Two different fiber arrangements with 61 or 22 aluminum fibers were employed for the architectured samples. Experimentally, tensile tests on the two types of composites show that the flow stress of architectured configurations is markedly higher than that of the linear rule of mixtures’ prediction. Transverse stress components and processing-induced residual stresses are then studied via numerical simulations to assess their potential effect on this enhanced strength. A set of elastic-domain and elastoplastic simulations were performed to account for the influence of Young’s modulus and volume fraction of each phase on the magnitude of transverse stresses and how theses stresses contribute to the axial stress-strain behavior. Besides, residual stress fields of different magnitude with literature-based distributions expected for cold-drawn wires were defined. The findings suggest that the improved yield strength of architectured Cu-Al wires cannot be attributed to the weak transverse stresses developed during tensile testing, while there are compelling implications regarding the strengthening effect originating from the residual stress profile. Finally, the results are discussed and concluded with a focus on the role of architecture and residual stresses. Keywords: wire drawing; Cu-Al composite wires; finite element analysis 1. Introduction Abundant copper demand for electrical applications from various sectors has prompted manufacturers to reduce material costs by replacing this rather expensive and high-density metal partly or entirely. Lower-density and more affordable aluminum-copper (Al-Cu) composite wire is an example of such efforts. The following paragraphs provide a sum- mary of the different features of Al-Cu wires and several other similar composite systems (developed by various techniques) already investigated. The missing aspects and the property of interest to be researched in the current work are then presented at the end of this section. Among those already-studied features are the investigations covering the mechanical behavior and finite element modelling of the manufacture processes of severely cold worked composite systems akin to the one under study in this work. Khosravifard and Ebrahimi [1] investigated the parameters affecting the interface strength of extruded Al/Cu clad bimetal rods along with FEM analysis of the extrusion process. Feng et al. [2] examined the compressive mechanical behavior of Al/Mg composite rods with different types of Al sleeve. Gu et al. [3] modelled the elastic behavior of architectured and nanostructured Cu– Nb composite wires produced by accumulative drawing and bundling (a severe plastic Materials 2021, 14, 6305. https://doi.org/10.3390/ma14216305 https://www.mdpi.com/journal/materials