Details
| Original language | English |
|---|---|
| Pages (from-to) | 126-137 |
| Number of pages | 12 |
| Journal | Acta materialia |
| Volume | 79 |
| Publication status | Published - 15 Oct 2014 |
Abstract
This study focuses on the functional stability of [0 0 1]-oriented Fe 41Ni28Co17Al11.5Ta2.5 (at.%) single crystals. It is shown that functional degradation of aged FeNiCoAlTa, containing fine dispersed γ′-particles ∼5-8 nm in diameter is caused by the interaction of different martensite variants under cyclic loading in tension. Superelastic cycling experiments up to 4.5% total strain resulted in the accumulation of permanent strain mainly caused by the formation of retained martensite. In situ observations were conducted in order to evaluate the local strain evolution and martensite variant interactions on the meso- and microscale. Optical microscopy and transmission electron microscopy observations revealed various differently oriented martensite variants which were retained upon 100 superelastic cycles. In addition, fine martensitic structures remaining in the vicinity of the γ′ precipitates were found after mechanical cycling, which are shown to be important for cyclic degradation in Fe-based shape memory alloys.
Keywords
- Fatigue, Internal friction, Martensitic phase transformation, Precipitates, Shape memory alloys
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Materials Science(all)
- Ceramics and Composites
- Materials Science(all)
- Polymers and Plastics
- Materials Science(all)
- Metals and Alloys
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In: Acta materialia, Vol. 79, 15.10.2014, p. 126-137.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Cyclic degradation mechanisms in aged FeNiCoAlTa shape memory single crystals
AU - Krooß, P.
AU - Somsen, C.
AU - Niendorf, T.
AU - Schaper, M.
AU - Karaman, I.
AU - Chumlyakov, Y.
AU - Eggeler, G.
AU - Maier, H. J.
N1 - Funding information: Financial support by Deutsche Forschungsgemeinschaft under Grant No. MA 1175/33-1 is gratefully acknowledged. The reported study was partially supported by RFBR Project No. 12-08-91331 NNIO-a. I.K. acknowledges the financial support by the US National Science Foundation—International Materials Institute Program through the grant no. DMR 08-44082, Division of Materials Research, Arlington, Virginia. C.S. and G.E. acknowledge funding by the Deutsche Forschungsgemeinschaft (DFG) in the framework of FOR 1766, Project TP2.
PY - 2014/10/15
Y1 - 2014/10/15
N2 - This study focuses on the functional stability of [0 0 1]-oriented Fe 41Ni28Co17Al11.5Ta2.5 (at.%) single crystals. It is shown that functional degradation of aged FeNiCoAlTa, containing fine dispersed γ′-particles ∼5-8 nm in diameter is caused by the interaction of different martensite variants under cyclic loading in tension. Superelastic cycling experiments up to 4.5% total strain resulted in the accumulation of permanent strain mainly caused by the formation of retained martensite. In situ observations were conducted in order to evaluate the local strain evolution and martensite variant interactions on the meso- and microscale. Optical microscopy and transmission electron microscopy observations revealed various differently oriented martensite variants which were retained upon 100 superelastic cycles. In addition, fine martensitic structures remaining in the vicinity of the γ′ precipitates were found after mechanical cycling, which are shown to be important for cyclic degradation in Fe-based shape memory alloys.
AB - This study focuses on the functional stability of [0 0 1]-oriented Fe 41Ni28Co17Al11.5Ta2.5 (at.%) single crystals. It is shown that functional degradation of aged FeNiCoAlTa, containing fine dispersed γ′-particles ∼5-8 nm in diameter is caused by the interaction of different martensite variants under cyclic loading in tension. Superelastic cycling experiments up to 4.5% total strain resulted in the accumulation of permanent strain mainly caused by the formation of retained martensite. In situ observations were conducted in order to evaluate the local strain evolution and martensite variant interactions on the meso- and microscale. Optical microscopy and transmission electron microscopy observations revealed various differently oriented martensite variants which were retained upon 100 superelastic cycles. In addition, fine martensitic structures remaining in the vicinity of the γ′ precipitates were found after mechanical cycling, which are shown to be important for cyclic degradation in Fe-based shape memory alloys.
KW - Fatigue
KW - Internal friction
KW - Martensitic phase transformation
KW - Precipitates
KW - Shape memory alloys
UR - http://www.scopus.com/inward/record.url?scp=84905864817&partnerID=8YFLogxK
U2 - 10.1016/j.actamat.2014.06.019
DO - 10.1016/j.actamat.2014.06.019
M3 - Article
AN - SCOPUS:84905864817
VL - 79
SP - 126
EP - 137
JO - Acta materialia
JF - Acta materialia
SN - 1359-6454
ER -