الفهرس 
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Abstract
owadays, severe plastic deformation especially equal channel angular. Nowadays, severe plastic deformation especially equal channel angular pressing (ECAP) is an important grain refinement technique. Besides, Cu-Sn alloys are used as bearing materials. However, few research works on ECAP processing of such alloys are available. Cu-2, 5 and 10%Sn alloys are ECAP processed following route ”A” at room temperature up to 5, 4, and 1 pass, respectively, through a die of 120o inner angle and 20oouter angle. The microstructure is studied before and after ECAP processing using optical microscope. Moreover, tensile properties, hardness, wear rate and surface roughness are measured It is found that, the grain size is refined and brittle ε precipitate is disintegrated with increasing both Sn content and number of ECAP passes .Also, the ultimate tensile stress, proof strength, and hardness of Cu-2, 5 and 10%Sn alloys increase with Sn content, and ECAP pass number. However, UTS of 2%Sn alloy reaches a maximum value after 4 passes, and that of 5%Sn alloy after only 3 passes. Besides, the elongation percent of Cu-2, 5 and 10%Sn alloys decreases strongly after the first ECAP pass. The elongation of Cu-2 and 5%Sn alloys begin to increase after second pass until fifth and fourth pass, respectively. Furthermore, remarkable increase of hardness takes place with increasing Sn content and number of ECAP passes, and the wear resistance is improved by increasing Sn content and the number of ECAP passes especially after first pass. However ,remarkable decrease is observed in surface roughness (Ra) of Cu-2%, 5% and 10%Sn by decreasing Sn content and by increasing the number of ECAP passes.