The improved superelasticity of NiTi alloy via electropulsing treatment for minutes

R. F. Zhu, J. N. Liu, G. Y. Tang, San-Qiang Shi, Mingwang Fu, Zion Tsz Ho Tse

Research output: Journal article publicationJournal articleAcademic researchpeer-review

23 Citations (Scopus)

Abstract

Mechanical testing, transmission electron microscopy, X-ray and electrical resisitivity measurement were employed to study the superelasticity and microstructure of cold-rolled NiTi shape memory alloy subjected to electropulsing treatment (EPT) for more than 2.5 min. The best superelasticity with 8% of recovery strain is acquired due to recrystallization and aging of the NiTi alloy under electropulsing. The band microstructure of NiTi alloy cold-rolled has been changed to the equiaxed grains after EPT and the average size of NiTi alloy with the best superelasticity reaches to 40 nm. In addition, the X-ray pattern, electrical resistivity change and the upper plateau strength of the electropulsing processed NiTi alloy indicate the Ni4Ti3and Ni3Ti precipitates are produced respectively for the NiTi alloy treated by electropulsing with the frequency of 150 and 350 Hz. Furthermore, the decrease of electrical resistivity of the NiTi alloy processed by with the frequency of 250 Hz shows the coherent relationship between austenite and Ni4Ti3changes to the incoherent one in between.
Original languageEnglish
Pages (from-to)225-231
Number of pages7
JournalJournal of Alloys and Compounds
Volume584
DOIs
Publication statusPublished - 1 Jan 2014

Keywords

  • Electropulsing treatment
  • Nickel-titanium alloy
  • Recrystallization
  • Superelasticity

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry

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