The contribution of long-period stacking-ordered structure (LPSO) to high strength-high ductility combination and nanoscale deformation behavior of magnesium-rare earth alloy

Abstract The nanoscale deformation behavior of high strength (240 MPa)-high ductility (21.4%) combination Mg-rare earth alloy with long-period stacking-ordered structure was studied via nanoindentation and electron microscopy, and the behavior compared with the low strength (65 MPa)-good ductility (15%) alloy without LPSO structure. In non-LPSO alloy, basal slip mainly occurred, while in LPSO-containing alloy, the LPSO changed the deformation mechanism to extensive non-basal slip and deformation twinning. The intrinsic good plasticity of LPSO and its impact on the deformation mechanism of Mg matrix contributed to superior mechanical properties and nanoscale deformation behavior of Mg-rare earth alloys, without compromising the ductility.