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 language | English |
|---|---|
| Pages (from-to) | 6006-6011 |
| Number of pages | 6 |
| Journal | Materials Science and Engineering A |
| Volume | 528 |
| Issue number | 18 |
| DOIs | |
| Publication status | Published - 15 Jul 2011 |
Keywords
- Microstructure
- Microwave sintering
- Phase transformation
- Porous NiTi
- Shape memory alloys
ASJC Scopus subject areas
- General Materials Science
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering