TY  - JOUR
AU  - Yang, Qiang
AU  - Lv, Shuhui
AU  - Yan, Zixiang
AU  - Xie, Zefeng
AU  - Qiu, Xin
PY  - 2024
TI  - Exceptional reversed yield strength asymmetry in a rare-earth free Mg alloy containing quasicrystal precipitates
JO  - Journal of Magnesium and Alloys
SN  - 2213-9567
SP  - 687
EP  - 699
VL  - 12
IS  - 2
AB  - This work reports an exceptional reversed yield strength asymmetry at room temperature for a rare-earth free magnesium alloy containing a mass of fine dispersed quasicrystal (I-phase) precipitates. Although exhibiting traditional basal texture, it owns an exceptional CYS/TYS as high as ~1.17. Electron back-scattered diffraction (EBSD) and transmission electron microscopy (TEM) examinations indicate pyramidal < c + a > and prismatic < c > dislocations plus tensile twinning being activated after immediate yielding in compression while basal and non-basal < a > dislocations in tension. I-phase particles transferred the concentrated stress by self-twinning to provide the driving force for tensile twin initiating in neighboring grains, thereby significantly increasing the critical resolved shear stress of tensile twinning to possibly the level of pyramidal < c + a > slip, finally leading to the dominance of pyramidal < c + a > slip plus tensile twinning in texture grains. This results in a higher contribution on yield strength by ~55 MPa in compression than in tension, which reasonably agrees with the experimental yield strength difference (~38 MPa). It can be concluded that I-phase particles influence deformation modes in tension and in compression, finally result in reversed yield strength asymmetry.
UR  - https://doi.org/10.1016/j.jma.2022.10.005
DO  - 10.1016/j.jma.2022.10.005