Publication details
Ductility improvement of Mg alloys by solid solution: Ab initio modeling, synthesis and mechanical properties
| Authors | |
|---|---|
| Year of publication | 2014 |
| Type | Article in Periodical |
| Magazine / Source | ACTA MATERIALIA |
| Citation | |
| Doi | http://dx.doi.org/10.1016/j.actamat.2014.02.011 |
| Keywords | Magnesium; Rare-earth elements; Ductility; Modeling; Ab initio |
| Description | The I-1 intrinsic stacking fault energy (I-1 SFE) serves as an alloy design parameter for ductilizing Mg alloys. In view of this effect we have conducted quantum mechanical calculations for Mg15X solid-solution crystals (X=Dy, Er, Gd, Ho, Lu, Sc, Tb, Tm, Nd, Pr, Be, Ti, Zr, Zn, Tc, Re, Co, Ru, Os, Tl). We find that Y, Sc and all studied lanthanides reduce the I-1 SFE and render hexagonal closed-packed (hcp) and double hcp phases thermodynamically, structurally and elastically similar. Synthesis, experimental testing and characterization of some of the predicted key alloys (Mg-3Ho, Mg-3Er, Mg-3Tb, Mg-3Dy) indeed confirm reduced I-1 SFEs and significantly improved room-temperature ductility by up to 4-5 times relative to pure Mg, a finding that is attributed to the higher activity of non-basal dislocation slip. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. |