Texture and fatigue behavior of ultrafine grained copper produced by ECAP Oscar Fabián Higuera-Cobos a,b,n , Jonathan Antonio Berríos-Ortiz c , José María Cabrera a,d a Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica, ETSEIB – Universidad Politécnica de Cataluña, Av. Diagonal 647, 08028 Barcelona, Spain b Facultad de Ingeniería Mecánica, Universidad Tecnológica de Pereira, Vereda La Julita, Pereira, Colombia c Facultad de Ingeniería y Arquitectura, Escuela de Ingeniería Mecánica, Universidad de El Salvador, El Salvador d Fundació CTM Centre Tecnológic, Plaça de la Ciència 2, 08243 Manresa, Spain article info Article history: Received 19 March 2014 Received in revised form 5 May 2014 Accepted 6 May 2014 Available online 14 May 2014 Keywords: Equal channel angular pressing (ECAP) Inverse Pole Figures (IPF) Copper Texture Orientation Distribution Function (ODF) High-cycle fatigue abstract Electrolytic Tough Pitch (ETP) and Fire Refined High Conductivity (FRHC) copper samples were severely deformed by equal channel angular pressing (ECAP) and the effect of plastic deformation on the microstructure, texture and fatigue was investigated. The microstructural behavior was determined by analysis of the final texture through Inverse Pole Figures (IPF) and Orientation Distribution Function (ODF) maps, which revealed a marked decrease in the normal grain size of the ECAPed coppers and also the presence of recrystallization processes. The effect of the initial texture on the evolution of the texture after 8 ECAP passes for the two coppers was also analyzed. The results showed that the annealed materials presented a marked anisotropy, with a texture controlled by the 〈110〉 fiber. Additionally, the fatigue behavior of ultrafine grained coppers produced by ECAP was discussed briefly with respect to the macroscopic shear banding and fatigue lives. Experimental results also suggest that the fatigue behavior of ultrafine grained coppers processed by ECAP is quite different from conventional grained coppers, as the deformed materials presented a significant increase in the fatigue limit. & 2014 Elsevier B.V. All rights reserved. 1. Introduction Presently, due to the rapid development of the electrical and electronic industries, there is a high demand for materials that combine both high strength and good electrical conductivity, which has led to the development of pure Cu or Al with ultrafine or nanometric grain sizes. Such materials can be developed through severe plastic deformation (SPD) techniques [1]. Among the SPD methods, the equal channel-angular pressing (ECAP) technique is considered the most effective in terms of the amount of material used for the production of bulk metals with ultrafine grains [2]. Through this technique a large amount of shear strain is introduced in the processed samples, with no change in the shape of the workpiece, modifying the microstructure of the processed material and resulting in improvements in both the physical and mechanical properties (tensile/compression strength, yield stress, elongation and fatigue life). Besides the improvements in the physical and mechanical properties, as a consequence of the ECAP deformation, the materi- als develop a crystallographic texture, due to crystal reorientation, which is related to the dominant slip systems given by the crystallographic structure. Also, additional texture components may be developed, depending on the processing conditions and on the occurrence of the recrystallization processes or mechanical twinning. The evolution of the deformation texture with strain has been subjected to various investigations [3–5]. Recently, research focused on fatigue of ultrafine grained materi- als has increased noticeably, due to the key influence of fatigue properties on the use of these materials in practical applications. Fatigue can be associated with cumulative damage processes in materials, resulting in the fracture of a given material under the application of cyclical stress levels below the static tensile strength. Total fatigue life has conventionally been divided into two regions corresponding to the time required: first for crack nucleation and then for crack propagation. In order to delay the initiation of cracks, the materials should exhibit high mechanical resistance, while large ductility allows greater tolerance to the propagation of the crack. Ultrafine grained materials obtained by SPD, which can be associated with a combination of high strength and good ductility, suggest the possibility of a significant improvement in fatigue life. A correlation Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/msea Materials Science & Engineering A http://dx.doi.org/10.1016/j.msea.2014.05.011 0921-5093/& 2014 Elsevier B.V. All rights reserved. n Corresponding author at: Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica, ETSEIB – Universidad Politécnica de Cataluña, Av. Diagonal 647, 08028 Barcelona, Spain. Tel.: þ34 57 63137124x111; fax: þ34 57 63137362. E-mail addresses: osfahico@gmail.com (O.F. Higuera-Cobos), jose.maria.cabrera@upc.es (J.M. Cabrera). Materials Science & Engineering A 609 (2014) 273–282