CYCLIC PLASTIC BEHAVIOR AND FATGIUE LIFE OF AZ91 ALLOY IN AS-CAST AND ULTRAFINE-GRAINED STATE

• Main Authors: Stanislava Fintová, Ludvík Kunz
• Format: Article
• Language: English
• Published: Univerzity of Zilina. Faculty of Mechanical Engineering 2014-06-01
• Series: Materiálové Inžinierstvo
• Subjects: AZ91; ECAP; bimodal structure; fatigue; plastic deformation; crack initiation
• Online Access: http://ojs.mateng.sk/index.php/Mateng/article/view/143

<p>Fatigue properties of magnesium alloy AZ91 in as-cast and in ultrafine-grained state prepared by equal channel angular pressing were investigated. The fatigue strength in the low-cycle fatigue region was found to be substantially improved by the severe plastic deformation, whereas the improvement in the high-cycle fatigue region is negligible. The cyclic plastic response in both states is qualitatively similar; short initial softening is followed by a long cyclic hardening. The observed fatigue behavior was discussed in terms of specific microstructural features of both states and on the basis of cyclic slip localization and fatigue crack initiation.</p><p> </p>