Effects of cerium addition on non-basal slip in magnesium single crystals

Cerium, a rare earth element, was alloyed at various ratios with magnesium to create Mg-Ce single crystals which were then subjected to [1-bar100] and [112-bar0] tensile tests to clarify effects of cerium on activation of non-basal slips at room temperature. Mg-0.016 mol%Ce alloys yielded due to {101-bar1} twins in [1-bar100] tension tests. Mg-0.052 mol%Ce single crystals yielded due to {112-bar2}<1-bar1-bar23> second order pyramidal slip (SPCS), similar to pure magnesium single crystals, in [112-bar0] tensile tests. Cerium addition decreased critical resolved shear stresses (CRSS) for {101-bar1} twinning and SPCS. The decrease in CRSS for SPCS likely results from the frequency of sessile (c+a) dislocations decreasing with decreasing stacking fault energy of second order pyramidal planes. (author)