Ratcheting Strain and Microstructure Evolution of AZ31B Magnesium Alloy under a Tensile-Tensile Cyclic Loading

Materials

Liyong Sun¹  Wenxian Wang²  Jun Zhou²  Zhifeng Yan²  Xiuli He²  Hongxia Zhang²  Peng Dong²  Denghui Wang² 

[1] School of Engineering, The Behrend College, Pennsylvania State University Erie, Erie, PA 16563, USA;Shanxi Key Laboratory of Advanced Magnesium-Based Materials, School of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China;

关键词: AZ31B magnesium alloy;    ratcheting strain;    microstructure change;   

DOI  :  10.3390/ma11040513

来源: DOAJ

【 摘 要 】

In this paper, studies were conducted to investigate the deformation behavior and microstructure change in a hot-rolled AZ31B magnesium alloy during a tensile-tensile cyclic loading. The relationship between ratcheting effect and microstructure change was discussed. The ratcheting effect in the material during current tensile-tensile fatigue loading exceeds the material’s fatigue limit and the development of ratcheting strain in the material experienced three stages: initial sharp increase stage (Stage I); steady stage (Stage II); and final abrupt increase stage (Stage III). Microstructure changes in Stage I and Stage II are mainly caused by activation of basal slip system. The Extra Geometrically Necessary Dislocations (GNDs) were also calculated to discuss the relationship between the dislocation caused by the basal slip system and the ratcheting strain during the cyclic loading. In Stage III, both the basal slip and the {11−20} twins are found active during the crack propagation. The fatigue crack initiation in the AZ31B magnesium alloy is found due to the basal slip and the {11−20} tensile twins.

【 授权许可】

Unknown