Abstract

Although laser welding is probably the most used joining technique for NiTi shape memory alloys there is still a lack of understanding about the effects of laser welding parameters on the microstructural induced changes: in both the heat affected and fusion zones martensite may be present, while the base material is fully austenitic. Synchrotron X-ray diffraction was used for fine probing laser welded NiTi joints. Through Rietveld refinement the martensite and austenite phase fractions were determined and it was observed that the martensite content increases towards the weld centreline. This is related to a change of the local transformation temperatures on these regions, which occurs due to compositional variation in those regions. The martensite phase fraction in the thermally affected regions may have significant implications on functional properties on these joints.

Original languageEnglish
Pages (from-to)148-151
Number of pages4
JournalMaterials Characterization
Volume119
DOIs
Publication statusPublished - 1 Sep 2016

Keywords

  • Laser welding
  • Phase fraction
  • Phase transformations
  • Shape memory alloys (SMA)
  • Synchrotron radiation

Fingerprint Dive into the research topics of 'Effect of laser welding parameters on the austenite and martensite phase fractions of NiTi'. Together they form a unique fingerprint.

  • Cite this