Effects of Cerium Addition on Non-basal Slip in Magnesium Single Crystals+1

Abstract

Cerium, a rare earth element, was alloyed at various ratios with magnesium to create MgCe single crystals which were then subjected to [1100] and [1120] tensile tests to clarify effects of cerium on activation of non-basal slips at room temperature. Mg0.016mol%Ce alloys yielded due to f1011 - g twins in '1100 - ] tension tests. Mg0.052mol%Ce single crystals yielded due to f1122 - gh1-123 - i second order pyramidal ©c+aª slip (SPCS), similar to pure magnesium single crystals, in '1120 - ] tensile tests. Cerium addition decreased critical resolved shear stresses (CRSS) for f1011 - g 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.