Serrated flow in nanostructured binary Mg-Al alloys

Article history: Received 2 August 2016 Received in revised form 14 September 2016 Accepted 15 September 2016 Available online xxxx Serrated flow, also known as the Portevin-Le Chatelier effect, has been extensively investigated in binary Mg-alloys such asMg-Ag,Mg-Y andMg-Li alloys. Interestingly, however, this effect has not been observed inMg-Al alloys. In this work, we report the appearance of serrations in nanostructured Mg-Al alloys processed by cryomilling and spark-plasma-sintering during in-situ SEM microcompression tests at room temperature and strain rates between 2× 10 and 10 s. The observed serrated stress-strain behavior is attributed to the dynamic strain aging bywhich interstitial O and/or N impurities introduced during cryomilling diffuse and interact with in-grown dislocations during deformation. © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.