Deformation mode transition of Mg3Li alloy: An in situ neutron diffraction study

• Basal slip, tensile twinning and prismatic slip contribute to the plastic deformation at different strain stages.
• Non basal slip along with {101¯2} twinning induce the anelasticity and stress relaxation, leading to a clear hysteresis loop.
• Stress redistribution continuously occurs between soft and hard grain orientations, leading to deformation mode transition.

Deformation mode transition of Mg3Li alloy was investigated using in situ neutron diffraction along with texture characterization. Lattice strain and texture evolution were used as an indicator to tailor the deformation mode under uniaxial tension. It is shown that basal slip, tensile twinning and prismatic slip contribute to the plastic deformation at different stages. A clear hysteresis loop at plastic strain of about 1% is observed during loading/unloading, which is ascribed to the anelasticity resulting from {101¯2} twins upon unloading. Load redistribution continuously occurs between soft and hard grain orientations and the prismatic slip is dominated around the yield point.