Reduction of environmentally induced cracking of laser-welded shape memory NiTi wires via post-weld heat-treatment

C. W. Chan, Hau Chung Man

Research output: Journal article publicationJournal articleAcademic researchpeer-review

8 Citations (Scopus)

Abstract

In this study, the environmentally induced cracking behavior of the NiTi weldment with and without post-weld heat-treatment (PWHT) in Hanks' solution at 37.5. °C at OCP was studied by tensile and cyclic slow-strain-rate tests (SSRT), and compared with those tested in oil (an inert environment). Our previous results in the tensile and cyclic SSRT showed that the weldment without PWHT showed high susceptibility to the hydrogen cracking, as evidenced by the degradation of tensile and super-elastic properties when testing in Hanks' solution. The weldment after PWHT was much less susceptible to hydrogen attack in Hanks' solution as no obvious degradation in the tensile and super-elastic properties was observed, and only a very small amount of micro-cracks were found in the fracture surface. The susceptibility to hydrogen cracking of the NiTi weldment could be alleviated by applying PWHT at the optimized temperature of 350. °C after laser welding.
Original languageEnglish
Pages (from-to)388-394
Number of pages7
JournalMaterials Science and Engineering A
Volume588
DOIs
Publication statusPublished - 20 Dec 2013

Keywords

  • Hydrogen embrittlement
  • Laser welding
  • NiTi
  • Post-weld heat-treatment
  • Shape memory alloys

ASJC Scopus subject areas

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

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