Microstructure and properties of Mg-Li-Zn alloy sheets with Mn addition

Mg-9%Li-2%Zn(wt%),alloys was produced and rolled to thin sheet at room temperature.Adding Mn from 0.2%～1.5% to the alloy can refine grains.The effect is the best with Mn content being 0.2%～0.5%.Mn addition can improve mechanical properties of the alloys at room temperature.Uniaxial tensile tests are carried out at room temperature.The tensile strengthen and yield strength of the alloys with 0.5 % Mn addition may increase 33.5% and 25.8%,respectively.Both the strength and the elongation decrease with Mn content rising.It is clarified that adsorption of Mn on the grain boundary makes grains refined and improves the tensile properties of the sheets,but much hard particles of MgMn_2O_4 and Li_0.5MnO_2 worsen the properties.