Cryogenic Deformation Behavior of a Dual-Phase Mg–Li Alloy Investigated by In-Situ Neutron Diffraction

Mg and its alloys commonly exhibit inadequate formabilityFormability due to the limited availability of deformation modes in hcp phase. The addition of Li can stabilize a bcc phase in Mg alloysMagnesium alloys (Mg alloys) at room temperature, resulting in dual-phase (hcp + bcc) Mg–Li alloysMg-Li alloys that possess excellent formabilityFormability. However, these Mg-Li alloys exhibit poor work-hardening ability due to the dislocationDislocation recovery resulting in the low strength at room temperature. Considering that the dislocationDislocation recovery can be suppressed at cryogenic temperatures and the deformation mechanisms may vary with temperature, we tried to investigate the deformation behaviorDeformation behavior of a commercial LZ91 alloy (Mg–9Li–1Zn, wt%) at cryogenicCryogenic deformation behavior temperatures. In-situ neutron diffractionNeutron diffraction experiments during tensile deformation at 20, 77, and 298 K were performed by a time-of-flight engineering neutron diffractometer “TAKUMI” at J-PARC. The temperature-dependent deformation mechanisms in LZ91 alloy will be discussed based on the evolutions of phase stress, peak width, and textureTexture during deformation.