Microstructural evolution in a superelastic metastable beta-Ti alloy

James Coakley*, Dieter Isheim, Anna Radecka, David Dye, Howard J. Stone, David N. Seidman

*Corresponding author for this work

Research output: Contribution to journalArticle

7 Scopus citations

Abstract

The microstructural evolution of Ti-24Nb-4Zr-8Sn wt.% during low-temperature ageing is examined by atom-probe tomography (APT) and X-ray diffraction (XRD). This ageing is deleterious to the desirable mechanical properties, such as ultra-low elastic modulus and superelasticity. Initially, the cold-rolled alloy possesses a martensitic α′′-precipitate/β-matrix microstructure. On ageing, Ti-rich/solute-lean precipitates grow in linear arrangements, which are likely associated with dislocations. Additionally, the composition and number density of Nb-rich domains (which are associated with superelasticity) are quantified for the first time. The domains are unstable, but decrease in number density during ageing, causing the deterioration in mechanical properties.

Original languageEnglish (US)
Pages (from-to)87-90
Number of pages4
JournalScripta Materialia
Volume128
DOIs
StatePublished - Feb 1 2017

    Fingerprint

Keywords

  • Ageing
  • Atom-probe tomography
  • Martensitic phase transformation
  • Precipitation
  • Titanium alloys

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys

Cite this