The Influence of α′ (bcc) Martensite on the Dynamic and Magnetic Response of Powder Metallurgy FeMnSiCrNi Shape Memory Alloys
| Autor: | R. I. Comăneci, Mihai Mocanu, Burak Özkal, M. Grigoraș, L. G. Bujoreanu, Bogdan Pricop, Elena Mihalache, Firuța Borza |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
010302 applied physics
Austenite Materials science 020502 materials Close-packing of equal spheres 02 engineering and technology Shape-memory alloy Cubic crystal system 01 natural sciences 0205 materials engineering Phase (matter) Martensite Powder metallurgy 0103 physical sciences Deformation (engineering) Composite material |
| Zdroj: | The Minerals, Metals & Materials Series ISBN: 9783319769677 |
| DOI: | 10.1007/978-3-319-76968-4_16 |
| Popis: | In FeMnSi-based SMAs the “executive” phase is e (hexagonal close packed, hcp) stress induced martensite which retransforms to γ (face center cubic, fcc) austenite during heating, causing free-recovery shape memory effect (SME). At low Mn content or high deformation degrees, α′ (body center cubic, bcc) martensite can be additionally induced by cooling or deformation, being considered as detrimental for the magnitude of SME. In the case of powder metallurgy (PM) Fe-14Mn-6Si-9Cr-5Ni (wt%) SMAs containing 5 fractions of mechanically alloyed (MA’ed) powders (0–40%vol.) solution treated to 5 temperatures (700–1100 °C), large amounts, (20–90%) of α′-bcc martensite were detected by XRD and observed by SEM. Nevertheless, free-recovery SME was obtained and enhanced by training, up to bending strokes of 24 mm, developed with a rate of 1.71 mm/°C. The paper corroborates the qualitative and quantitative evolutions of α′, e and γ phases with DMA and thermomagnetic measurements performed on the 25 sets of specimens, during heating up to 500 °C. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|