Titre :

Multi-scale effects of the tool shape and length on the interfacial microstructure and the mechanical behaviour of Al2024/Ti-6Al-4V lap friction stir welds

Auteur(s) :

Geyer, Morgane [Auteur]
Institut Clément Ader [ICA]
Avettand-Fènoël, Marie-NoËlle [Auteur]
Unité Matériaux et Transformations (UMET) - UMR 8207
Vidal, Vanessa [Auteur]
Institut Clément Ader [ICA]
Rezaï-Aria, Fahrad [Auteur]
Institut Clément Ader [ICA]
Boher, Christine [Auteur]
Institut Clément Ader [ICA]

Titre de la revue :

Journal of Manufacturing Processes

Numéro :

113

Pagination :

360-372

Éditeur :

Society of Manufacturing Engineers

Date de publication :

2024-02-01

ISSN :

1526-6125

Discipline(s) HAL :

Chimie/Matériaux
Physique [physics]/Matière Condensée [cond-mat]/Science des matériaux [cond-mat.mtrl-sci]

Résumé en anglais : [en]

In this study, Al2024-T3 aluminium alloy and Ti-6Al-4V titanium alloy were lap jointed by friction stir welding (FSW). New insights are given into the multiscale effects of the pin tip shape and length on both the interface ...
Lire la suite >In this study, Al2024-T3 aluminium alloy and Ti-6Al-4V titanium alloy were lap jointed by friction stir welding (FSW). New insights are given into the multiscale effects of the pin tip shape and length on both the interface microstructure and the tensile-shear properties of dissimilar joints. The correlation between the stress distribution at the joint interface, governed by the pin shape, and the phase formation sequence was notably studied. The microstructure of the joints was examined from macro-to-nanoscale by optical microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM), while their mechanical properties were investigated with tensile-shear tests, coupled with digital image correlation (DIC). It was found that with a semi-spherical pin tip, the joint interface was sharp and semi-coherent. Al and Ti solid solutions were identified by HRTEM analysis over a distance of 10 nm on both sides of this interface. Conversely, a longer flat pin tip generated a 15 μm thick multi-layered interface containing Ti3Al, TiAl and TiAl3 intermetallic compounds. The effect of the welding conditions on the reaction kinetics during friction stir welding of Al/Ti alloys has been investigated. It was found that the intermetallic compounds were formed by atomic diffusion favoured by both temperature and plastic deformation. The interfacial joint microstructures were explained by the different stress and strain fields generated by the distinct pin tip shapes and by their different penetration depths in the Ti-6Al-4V bottom plate. Although these microstructural features at the joints interface very likely governed the tensile-shear properties of safe joints, they were, in this case, less critical than the hooks and the deformed Alclad layer which led to the joint fracture. Stronger and more ductile joints were obtained with the semi-spherical tip shorter pin. A maximum joint coefficient of 50 % compared to Al2024 base material was found. Some ways of optimization were finally proposed.Lire moins >

Langue :

Anglais

Comité de lecture :

Oui

Audience :

Internationale

Vulgarisation :

Non

Établissement(s) :

Université de Lille
CNRS
INRAE
ENSCL

Collections :

• Unité Matériaux et Transformations (UMET) - UMR 8207

Équipe(s) de recherche :

Métallurgie Physique et Génie des Matériaux

Date de dépôt :

2024-02-02T14:13:25Z
2024-02-05T10:34:18Z