Enhancement of plastic anisotropy and drastic increase in yield stress of Mg-Li single crystals by Al-addition followed by quenching

Strong orientation dependence of yield stress was found in a body-centered cubic (bcc)-structured Mg-Li alloy single crystal by adding 5 at.% of Al combined with rapid quenching, which was negligible in Mg-Li binary single crystals. Furthermore, the addition of 5 at.% of Al combined with rapid quenching caused an extreme increase in yield stress up to similar to 470 MPa; this compares to similar to 50 MPa in a Mg-Li binary crystal. Increased valence-electron to atom ratio and development of chemical modulation in the alloy by Al-addition are probable causes of the enhancement of plastic anisotropy and the drastic increase in yield stress, respectively. (C) 2019 Published by Elsevier Ltd on behalf of Acta Materialia Inc.