Susceptibility to environmentally induced cracking of laser-welded NiTi wires in Hanks' solution at open-circuit potential

C. W. Chan, Hau Chung Man, Tai Man Yue

Research output: Journal article publicationJournal articleAcademic researchpeer-review

11 Citations (Scopus)

Abstract

In the present study the tensile and super-elastic behaviours of laser-welded NiTi wires in Hanks' solution at open-circuit potential (OCP) were investigated using tensile and cyclic slow-strain-rate tests (SSRT). In comparison with NiTi weldment tested in oil (non-corrosive environment), the weldment in Hanks' solution suffered from obvious degradation in the tensile properties as evidenced by lower tensile strength, reduced maximum elongation, and a brittle fracture mode. Moreover, a larger residual strain was observed in the weldment after stress-strain cycles in Hanks' solution. In addition to the microstructural defects resulting from the welding process, the inferior tensile and super-elastic behaviours of the NiTi weldment in Hanks' solution could be attributed to the trapping of a large amount of hydrogen in the weld zone and heat-affected zone.
Original languageEnglish
Pages (from-to)38-47
Number of pages10
JournalMaterials Science and Engineering A
Volume544
DOIs
Publication statusPublished - 15 May 2012

Keywords

  • Hydrogen embrittlement
  • Nanoindentation
  • Shape memory alloys
  • Strain measurement
  • Welding

ASJC Scopus subject areas

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

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