Equal Channel Angular Pressing (ECAP) is a severe plastic process for achieving ultrafine grain materials without changing the sample dimensions. In this study ECAP process up to 20 passes (equal to strain of 12.6) was carried out with different routes A, B 30 , B 45 , B 60 and B C . In the ECAP die, the inner and outer angles of channel intersection were 120° and 20°, respectively. Rod copper billets with the purity of 99.9% and 20 mm diameter, 80 mm length were used as the experimental material. As the cross section of the specimens was circular, new routes with rotating angles of 30°, 45° and 60° in the same direction between consecutive passes were defined. Before each pass of the process, samples were lubricated with oil and graphite powder. As the original dimensions of the sample is unchanged, it is possible to repeat the process to high strains. Microstructure characterization of 20 passes ECAP samples with routes B 30 and B C were analyzed with Field Emission Scanning Electron Microscopy (FESEM). Tensile tests and hardness measurements were performed on the samples for evaluating their mechanical properties. In order to clarify the failure mode, fracture surfaces after tensile tests were observed by Scanning Electron Microscopy (SEM). Moreover, x-ray diffraction system equipped by goniometer was utilized to investigate the variation of texture of the samples. The results indicated that significant grain refinement was obtained by ECAP and the grain size decreased from 49 micron in original material to below 100 nm after 20 passes ECAP with route B C and a few hundred nm in 20 passes ECAP sample with route B 30 . After six passes the hardness of the sample was almost two times higher than the original sample. ECAP process results in significant increase in tensile strength but, elongation of the sample becomes less than half although there is no additional reduction in the ductility with increasing ECAP passes. In different routes, maximum tensile strength was achieved in different passes. These properties maybe explained by evaluation of microstructures. Different routes result in different textures in ECAP samples. Except route A, texture produced by other routes is asymmetric. In route A texture is symmetry about TD. Predominant texture is the same in different passes of route A. Maximum intensity in texture is achieved in sample extruded with route B C . Key words : Angular Extrusion, Copper, Hardness, Tensile Strength, Fractography, Texture
