Effect of back pressure on material flow and texture in ECAP of aluminum

6th International Conference on Nanomaterials by Severe Plastic Deformation

材料科学;化学

Panigrahi, A.^1 ; Scheerbaum, N.^2 ; Chekhonin, P.^3 ; Scharnweber, J.^3 ; Beausir, B.^4 ; Hockauf, M.^5 ; Sankaran, S.^6 ; Skrotzki, W.^3

Physik Nanostrukturierter Materialien, Fakultät für Physik, Universität Wien, A-1090 Wien, Austria^1

Globalfoundries, Fab 1, Dep. Integration, D-01109 Dresden, Germany^2

Institut für Strukturphysik, Technische Universität Dresden, D-01062 Dresden, Germany^3

Laboratoire d'Étude des Microstructures et de Mécanique des Matériaux (LEM3), Universite de Lorraine, Ile du Saulcy, F-57045 Metz, France^4

Chemnitzer Werkstoff- und Oberflächentechnik GmbH, D-09119 Chemnitz, Germany^5

Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036, India^6

关键词: Back pressures;    Coarse-grained;    Initial textures;    Material Flow;    Normal direction;    Rolling texture;    Shear texture components;    Texture gradient;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/63/1/012153/pdf
DOI  :  10.1088/1757-899X/63/1/012153

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Large billets (5 x 5 x 30) cm3of technically pure aluminum (AA 1050) taken from thick rolled sheets were deformed at room temperature by single pass equal-channel angular pressing (ECAP). ECAP was done at different back pressures (0-60 MPa) using a square die with channels intersecting at 90° in sharp corners. The normal direction of rolling was taken parallel to the transverse direction of ECAP. The flow pattern was visualized by marker lines on split billets. The initial texture of the coarse-grained rolled sheet was measured by neutron diffraction. After ECAP, X-ray diffraction was used to measure the texture gradient from top to bottom of the billets. The results show, that with increasing back pressure the corner gap is closed and the flow line pattern becomes more symmetric. The flow line exponent increases strongly from top to bottom of the billets. Moreover, the inhomogeneous deformed zone at the bottom of the billets becomes smaller. The texture changes from a typical rolling texture to a typical shear texture with the intensity of the different shear texture components changing with back pressure. For the ACcomponent splitting is observed. The texture changes are discussed considering Toth's flow line model and grain refinement.