Predicting the critical pre-aging time in ECAP processing of age-hardenable aluminum alloys

Age-hardenable Al alloys may be successfully processed by equal channel angular pressing (ECAP) at room temperature, if the processing is carried out immediately after water quenching from the solution treatment temperature. It is important to estimate the critical time for any age-hardenable alloys, since after this time, ECAP processing will cause catastrophic cracking or segmentation at room temperature. In this study, ECAP processing was carried out on two age-hardenable Al alloys (2014 and 7075) at room temperature. The results demonstrated that the critical time could be predicted successfully by using tensile test curves related to different times after quenching. It is also shown that room temperature ECAP processing of these materials for more than a single pass is not possible and causes damage. However, a single pass will have significant effects on the strength of the material. (C) 2011 Elsevier B.V. All rights reserved.