Formulation of anisotropic Hill criteria for the description of an aluminium alloy behaviour during the channel die compression test

• Published in: 10th Esaform Conference on Material Forming: Part A(AIP Conference Proceedings Volume 907) Vol. 907; no. 1; pp. 321 - 326
• Main Authors: Gavrus, A, Francillette, H
• Format: Journal Article
• Language: English
• Published: United States 01.01.2007
• Subjects: ALUMINIUM; ALUMINIUM ALLOYS; ANISOTROPY; COMPRESSION; CORRELATIONS; DEFORMATION; HARDENING; MATERIALS SCIENCE; MIXTURES; O CODES; ORIENTATION; PLASTICITY; STRAINS; STRESSES; TESTING; TEXTURE; VARIATIONS
• ISBN: 0735404143; 9780735404144
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/1.2729532

During the last years the study of the plastic deformation modes and the anisotropic mechanical behaviour of aluminium alloys have been the subject of many investigations. This paper deals with a phenomenological identification of an anisotropic Hill constitutive equation of aluminium AU4G samples using a channel die compression device at room temperature. By considering the different possible orientations of the samples in the channel die device, three initial textures, named ND (normal direction Z), LD (longitudinal direction X) and TD (transverse direction Y), were defined with the corresponding stresses ND, LD and TD. To describe the anisotropy of the material, a quadratic Hill criteria is used. An Avrami type equation based on the mixture of the hardening and softening phenomena is used to describe variation of each stress component with the equivalent plastic strain. The identification of the parameters of the law is made using an identification software (OPTPAR) and a good correlation between the experimental stresses and computed ones is obtained. The variation of the Hill parameters with a proposed equivalent strain, describing the deformation history of the material, is analysed. Finally, using the expressions of F, G, H and N, the constitutive equation of the normal anisotropy in the plane XY is obtained.