  The cyclic deformation behavior of extruded Mg-8.5wt.%Al alloy with a
conventional extrusion texture and a modified texture is systematically
investigated by in-situ neutron diffraction and elastic viscoplastic
self-consistent (EVPSC) modeling incorporating a twinning/de-twinning (TDT)
scheme. The role of twinning and de-twinning on the deformation behavior of
Mg-8.5wt.% Al alloy is investigated in terms of the macroscopic stress-strain
response, the evolution of the activities of various deformation mechanisms,
the texture evolution, the evolution of the internal elastic strains, and the
evolution of the diffraction peak intensities. The alloy with the conventional
extrusion texture undergoes twinning during initial compression and de-twinning
during reverse tension. The same alloy does not favor twinning during initial
tension, but rather during reverse compression. The alloy with a modified
texture undergoes twinning during initial tension followed by detwinning during
reverse compression. The results provide insights into the effect of initial
texture, loading path, slip, twinning, de-twinning on the cyclic behavior of
magnesium.
