《925_Fatigue-properties-of-5056-Al-Mg-alloy-produced-by-equal-channel-angular-pressing》.pdfVIP

NanoStructured Materials, Vol. 11, No. 7, pp. 925–934, 1999 Elsevier Science Ltd Pergamon Copyright © 1999 Acta Metallurgica Inc. Printed in the USA. All rights reserved. 0965-9773/99/$–see front matter PII S0965-9773(99)00392-X FATIGUE PROPERTIES OF 5056 Al-Mg ALLOY PRODUCED BY EQUAL-CHANNEL ANGULAR PRESSING 1* 1 1 1 2 A. Vinogradov , S. Nagasaki , V. Patlan , K. Kitagawa and M. Kawazoe 1Department of Mechanical Systems Engineering, Kanazawa University, Kanazawa 920-5667, Japan 2Sendai Institute of Material Science and Technology, YKK Corporation, Miyagi 981-3341, Japan (Received June 15, 1999) (Accepted September 29, 1999) Abstract—The fatigue behaviour of the fine-grain 5056 Al-alloy processed by equal-channel angular pressing (ECAP) is explored. This material exhibits a slightly enhanced fatigue life at low stress amplitudes. However, no improvement in the fatigue limit is observed. Fatigue performance is discussed in terms of fatigue life, crack nucleation and propagation. Structural changes during fatigue are investigated by transmission electron microscopy. It is shown that the fine structure achieved during processing is unstable and tends to relax with cycling