| Abstract Scope |
In this study, the role of alloying elements Zn and Ca on the low cycle fatigue (LCF) behavior was investigated using a methodology employing in-Scanning Electron Microscopy (SEM) loading, quasi-in-situ SEM loading, and electron backscatter diffraction (EBSD). Fully reversed, strain-controlled LCF experiments were performed on unalloyed Mg, Mg-2Zn (wt.%), Mg-0.5Ca (wt.%), and Mg-2Zn-0.5Ca (wt.%). Total strain amplitudes ranging from 0.4-1.2% were employed to understand the role of plastic strain on deformation mechanisms and fatigue lifetime. Stress-strain hysteresis loops and strain life curves were constructed based on the Coffin-Manson relation to quantify and compare the fatigue behaviors between each alloy. In-SEM, quasi-in-situ SEM, and EBSD analysis were used to reveal the microstructural factors influencing LCF behavior and identify potential sites for fatigue crack initiation. The results suggested the difference in fatigue lives was influenced by differences in the active deformation mechanisms in each alloy. |