Equal channel angular pressing (ECAP) is a promising technique for production of ultrafine-grain materials of a few hundred nanometres size. In the present paper commercially pure aluminium billets were processed by ECAP up to 8 passes using the route BC in which the samples were rotated about the longitudinal axis by 90° in the same direction after each consecutive pressing. Electron backscattered diffraction (EBSD) was used to evaluate the microstructure of the aluminium. EBSD scans revealed a fairly homogeneous ultrafme grained microstructure after 8 passes. This analysis also showed that the fraction of high angle grain boundaries and average grain size were about 70 % and 1500 nm, respectively. Then, tensile properties of the aluminium billets were evaluated. The results represent that the yield stress of aluminium is increased significantly by about four times after application of four consecutive passes of ECAP and then it remains approximately constant.
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