Fabrication and characteristics of porous NiTi shape memory alloy synthesized by microwave sintering

Chak Yin Tang, L. N. Zhang, C. T. Wong, Kang Cheung Chan, Tai Man Yue

Research output: Journal article publicationJournal articleAcademic researchpeer-review

45 Citations (Scopus)

Abstract

Porous nickel titanium (NiTi) shape memory alloy (SMA) was successfully fabricated by microwave sintering method. This method allows formation of porous structures without using any pore-forming agents. Moreover, microwave sintering of NiTi SMA can be successfully performed at a relatively low sintering temperature of 850 °C and a short sintering time of 15. min. The pore characteristics, microstructure, phase transformation and stress-strain behavior of the porous NiTi SMA were investigated. The porous NiTi SMA exhibited porosity ratios from 27% to 48% and pore sizes range from 50 to 200 μm when using different sintering temperatures and holding times. The predominant B2 (NiTi) and B19′ (NiTi) phases were identified in the porous NiTi SMA. A multi-step phase transformation took place on heating and a two-step phase transformation took place on cooling of the porous NiTi SMA. The irrecoverable strains decreased with increasing sintering temperature, but the holding time had little effect on the stress-strain behavior at 60 °C.
Original languageEnglish
Pages (from-to)6006-6011
Number of pages6
JournalMaterials Science and Engineering A
Volume528
Issue number18
DOIs
Publication statusPublished - 15 Jul 2011

Keywords

  • Microstructure
  • Microwave sintering
  • Phase transformation
  • Porous NiTi
  • Shape memory alloys

ASJC Scopus subject areas

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

Cite this