Study of hot deformation of an Al-Cu-Mg alloy using processing maps and microstructural characterization

The forming behaviour of an Al–Cu–Mg alloy (Al 2024-T351) has been studied by processing maps and microstructural characterization. Torsion tests were conducted in the range 278–467 ◦C, between 2.1 and 25.6 s−1. Stress–strain curves obtained from the experiment data were fitted using the Garofalo eq...

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Bibliographic Details
Authors: Cepeda-Jiménez, C.M., Ruano, Oscar Antonio, Carsí, Manuel, Carreño, Fernando
Format: article
Status:Versión aceptada para publicación
Publication Date:2012
Country:España
Institution:Consejo Superior de Investigaciones Científicas (CSIC)
Repository:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/109997
Online Access:http://hdl.handle.net/10261/109997
Access Level:Open access
Keyword:Electron backscatter diffraction-EBSD
Mechanical characterization
Aluminium alloys
Hot deformation
Recrystallization
Processing maps
Description
Summary:The forming behaviour of an Al–Cu–Mg alloy (Al 2024-T351) has been studied by processing maps and microstructural characterization. Torsion tests were conducted in the range 278–467 ◦C, between 2.1 and 25.6 s−1. Stress–strain curves obtained from the experiment data were fitted using the Garofalo equation to obtain the constitutive parameters, obtaining a stress exponent of 6.1 and an activation energy of 180 kJ/mol. Electron backscatter diffraction (EBSD) was employed to characterize the microtexture and microstructure, before and after torsion testing, to evaluate the microstructural changes and instability phenomena. A peak ductility of the Al 2024 alloy was found at about 400 ◦C at all strain rates considered. According to the processing maps and microstructure observation, the optimum hot deformation condition for the Al 2024 alloy is in the range 360–410 ◦C and 2.1–4.5 s−1. Under these favourable conditions a uniform and fine grain size is obtained by extended dynamic recovery (DRV), which leads to the formation of subgrain boundaries that progressively transform at large strains into new high angle grain boundaries