Publications de Zhaoxuan Wu | EPFL Graph Search

Analysis of double cross-slip of pyramidal I < c plus a > screw dislocations and implications for ductility in Mg alloys

William Curtin, Zhaoxuan Wu, Rasool Ahmad

Solute accelerated cross-slip of pyramidal < c + a > screw dislocations has recently been recognized as a crucial mechanism in enhancing the ductility of solid-solution Mg alloys. In pure Mg, cross-slip is ineffective owing to the energy difference between ...

PERGAMON-ELSEVIER SCIENCE LTD2020

Design of Ductile Rare-Earth-Free Magnesium Alloys

William Curtin, Zhaoxuan Wu, Binglun Yin, Rasool Ahmad

Pure Mg has low ductility due to a transition of < c+a > pyramidal dislocations to a sessile basal-oriented structure. Dilute alloying generally improves ductility. Enhancement of pyramidal cross-slip from the lower-energy pyramidal II plane to the higher- ...

SPRINGER INTERNATIONAL PUBLISHING AG2020

Designing high ductility in magnesium alloys

William Curtin, Zhaoxuan Wu, Binglun Yin, Rasool Ahmad

The thermally activated pyramidal-to-basal (PB) transition of (c + a) dislocations, transforming glissile pyramidal dissociated core structures into sessile basal dissociated ones, lies at the origin of low ductility in pure magnesium (Mg). Solute-accelera ...

PERGAMON-ELSEVIER SCIENCE LTD2019

Mechanistic origin and prediction of enhanced ductility in magnesium alloys

William Curtin, Zhaoxuan Wu, Binglun Yin, Rasool Ahmad

American Association for the Advancement of Science2018

Pyramidal II to basal transformation of 'c plus a' edge dislocations in Mg-Y alloys

William Curtin, Zhaoxuan Wu, Rasool Ahmad

2018

Comprehensive first-principles study of stable stacking faults in hcp metals

William Curtin, Zhaoxuan Wu, Binglun Yin

The plastic deformation in hcp metals is complex, with the associated dislocation core structures and properties not well understood on many slip planes in most hcp metals. A first step in establishing the dislocation properties is to examine the stable st ...

Elsevier2017

First-principles calculations of stacking fault energies in Mg-Y, Mg-Al and Mg-Zn alloys and implications for < c plus a > activity

William Curtin, Zhaoxuan Wu, Binglun Yin

Mg-3wt.%RE alloys show substantially enhanced < c + a > activity as compared to pure Mg or other Mg-Al, Mg-Zn alloys of similar grain sizes. Activation of < c + a > slip has been postulated to be associated with the reduction of the basal Li stacking fault ...

Pergamon-Elsevier Science Ltd2017

Energetics of dislocation transformations in hcp metals

William Curtin, Zhaoxuan Wu, Binglun Yin

Dislocation core structures of hcp metals are highly complex and differ significantly among the hcp family. Some dislocations undergo unconventional transformations that have significant effects on the material plastic flow. Here, the energetics of disloca ...

Elsevier2016

Mechanism and energetics of < c plus a > dislocation cross-slip in hcp metals

William Curtin, Zhaoxuan Wu

Hexagonal close-packed (hcp) metals such as Mg, Ti, and Zr are lightweight and/or durable metals with critical structural applications in the automotive (Mg), aerospace (Ti), and nuclear (Zr) industries. The hcp structure, however, brings significant compl ...

National Academy of Sciences2016

Intrinsic structural transitions of the pyramidal I 〈c+a〉 dislocation in magnesium

William Curtin, Zhaoxuan Wu

The stability of a mixed < c + a > dislocation on the pyramidal I plane in magnesium is studied using molecular dynamics simulations. The dislocation is metastable and undergoes a thermally-activated transition to either a sessile, basal-dissociated < c + ...

Elsevier2016

The origins of high hardening and low ductility in magnesium

William Curtin, Zhaoxuan Wu

Magnesium is a lightweight structural metal but it exhibits low ductility-connected with unusual, mechanistically unexplained, dislocation and plasticity phenomena-which makes it difficult to form and use in energy-saving lightweight structures. We employ ...

Nature Publishing Group2015