en Research Paper Research Paper <strong><span lang="EN-GB" style="FONT-SIZE: 11pt FONT-FAMILY: "Times New Roman","serif" mso-ansi-language: EN-GB mso-fareast-language: EN-US mso-fareast-font-family: 'Times New Roman' mso-bidi-language: AR-SA">Abstract:</span><span lang="EN-GB" style="FONT-SIZE: 11pt FONT-FAMILY: "Times New Roman","serif" mso-ansi-language: EN-US mso-fareast-language: EN-US mso-fareast-font-family: 'Times New Roman' mso-bidi-language: AR-SA"> </span></strong><span lang="EN-GB" style="FONT-SIZE: 9pt FONT-FAMILY: "Times New Roman","serif" mso-ansi-language: EN-GB mso-fareast-language: EN-US mso-fareast-font-family: 'Times New Roman' mso-bidi-language: AR-SA">Equal channel angular extrusion (ECAE) is a promising technique for production of ultra fine-grain (UFG) materials of few hundred nanometers size. In this research, the grain refinement of aluminium strip is accelerated by sandwiching it between two copper strips and then subjecting the three strips to ECAE process simultaneously. The loosely packed copper-aluminium-copper laminated billet was passed through ECAE die up to 8 passes using the B_c route. Then, tensile properties and some microstructural characteristics of the aluminium layer were evaluated. The scanning and transmission electron microscopes, and X-ray diffraction were used to characterize the microstructure. The results show that the yield stress of middle layer (Al) is increased significantly by about four times after application of ECAE throughout the four consecutive passes and then it is slightly decreased when more ECAE passes are applied. An ultra fine grain within the range of 500 to 600 nm was obtained in the Al layer by increasing the thickness of the copper layers. It was observed that the reduction of grain size in the aluminium layer is nearly 55% more than that of a ECA-extruded single layer aluminium billet, i.e. extruding a single aluminium strip or a billet without any clad for the same amount of deformation. This behaviour was attributed to the higher rates of dislocations interaction and cell formation and texture development during the ECAE of the laminated composite compared to those of a single billet</span> Keywords: Severe plastic deformation; Laminated composite; Equal channel angular extrusion; UFG materials; Aluminium/Copper. 0 0 http://ijmse.iust.ac.ir/browse.php?a_code=A-10-3-108&slc_lang=en&sid=1 B. Tolaminejad 18003194753284600831 18003194753284600831 No A. Karimi Taheri ktaheri@sharif.edu 18003194753284600873 18003194753284600873 Yes H. Arabi 18003194753284600874 18003194753284600874 No M. Shahmiri 18003194753284600875 18003194753284600875 No