Evaluation of non-basal slip activity in rolled Mg-Li alloys

Tensile tests of rolled Mg-6.2mol%Li and Mg-11.7mol%Li alloys were carried out at room temperature to clarify effects of lithium addition on the relationship between mechanical properties and activities of slip systems. Ductility was found to increase with increasing lithium content. 0.2% proof stress increased when 6.2mol%Li was added. However, Mg-11.7mol%Li showed low 0.2% proof stress compared to pure magnesium. On the other hand, maximum stress decreased with increasing lithium content. Frequency of non-basal slips increased with increasing lithium content. Also, first order pyramidal <c+a> slip showed the highest frequency among non-basal slips in Mg-Li alloys. Critical resolved shear stresses for non-basal slips, which were reduced by lithium addition, resulted in high ductility and low tensile strength of magnesium.