Dual-phase nanostructuring as a route to high-strength magnesium alloys

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal

6 Scopus Citations
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Author(s)

  • Ge Wu
  • Ka-Cheung Chan
  • Linli Zhu
  • Ligang Sun
  • Jian Lu

Detail(s)

Original languageEnglish
Pages (from-to)80-83
Journal / PublicationNature
Volume545
Issue number7652
StatePublished - 4 May 2017

Abstract

It is not easy to fabricate materials that exhibit their theoretical â 'ideal' strength. Most methods of producing stronger materials are based on controlling defects to impede the motion of dislocations, but such methods have their limitations. For example, industrial single-phase nanocrystalline alloys and single-phase metallic glasses can be very strong, but they typically soften at relatively low strains (less than two per cent) because of, respectively, the reverse Hall-Petch effect and shear-band formation. Here we describe an approach that combines the strengthening benefits of nanocrystallinity with those of amorphization to produce a dual-phase material that exhibits near-ideal strength at room temperature and without sample size effects. Our magnesium-alloy system consists of nanocrystalline cores embedded in amorphous glassy shells, and the strength of the resulting dual-phase material is a near-ideal 3.3 gigapascals - making this the strongest magnesium-alloy thin film yet achieved. We propose a mechanism, supported by constitutive modelling, in which the crystalline phase (consisting of almost-dislocation-free grains of around six nanometres in diameter) blocks the propagation of localized shear bands when under strain; moreover, within any shear bands that do appear, embedded crystalline grains divide and rotate, contributing to hardening and countering the softening effect of the shear band.

Citation Format(s)

Dual-phase nanostructuring as a route to high-strength magnesium alloys. / Wu, Ge; Chan, Ka-Cheung; Zhu, Linli; Sun, Ligang; Lu, Jian.

In: Nature, Vol. 545, No. 7652, 04.05.2017, p. 80-83.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal