Investigation of the influence of ECAP and cryogenic rolling on the mechanical properties of the aluminium alloy 7075

The present study shows first results on the optimization of the mechanical properties of the high strength 7075 aluminium alloy, which is generally regarded as hard to deform. Two different deformation/ processing approaches are considered: On the one hand, the equal-channel angular pressing (ECAP) with different types of dies is utilized. On the other hand, (cold) rolling is performed with different, low temperatures (down to-196 degrees C). Various degrees of deformation are realized with both methods. By systematically adjusting the degree of deformation and the deformation temperature, the AA7075 alloy can be processed by ECAP. However, only minor improvements of the mechanical properties can be achieved by this approach. Cryogenic rolling results in a further increase of the degree of deformation, and also of strength and ductility. These results indicate that further improvements of the mechanical properties may well be achieved by ECAP processing at low temperatures. Both ECAP and cryogenic rolling offer a high potential for the production of ultrafine-grained high-strength aluminium alloys with novel properties.