Study by Experiments and Simulations of ECAE Deformation of Al-4%Cu Alloys

W SIGNORELLI, J; E A VIEIRA; A TURNER, P; M FERRANTE,; RAUL EDUARDO BOLMARO

REVISTA MATéRIA

Año: 2005 vol. 10 p. 585 - 599

1517-7076

This paper reports on equal channel angular extrusion experiments (ECAE). The material is a laboratory-cast Al-4%Cu alloy, in the T4 condition. The die has two channels with 15 x 15 mm2 square section, intersecting at 120o, and deformation was accomplished at room temperature and consisted of up to 5 passes with no rotation between passes. After deformation, all samples were subjected to hardness measurements and tensile tests. The several passes extrusion process has been simulated using Fine Element Methods (FEM). A finite element code specially developed to model large deformation processes, like the ones involved in forging, was used with tetrahedral elements and an elastic-viscoplastic material model. That kind of elements requires re-meshing in order to keep the coherence of the elements under high sustained deformation. The material model parameters were obtained from previous simple tensile mechanical tests. The simulation was used to assist in the selection of sample-cutting procedures for texture measurements and it will provide, in future works, the strain paths needed for self-consistent polycrystal modeling of texture development. Preferential orientations were measured by conventional x-ray diffraction techniques. Three pole figures, (111), (200) and (220) were used for Orientation Distribution Function calculation and analysis. Different regions were inspected to investigate the influence of different strain paths as simulated by FEM methods. Texture simulations were performed with a viscoplastic self-consistent model assuming homogeneous shear strain for each pass. Experimental textures were compared with simulations to evaluate the correctness of the whole approach.