Effect of Pre-straining on the Shape Recovery of Fe-Mn-Si-Cr-Ni Shape Memory Alloys
DSpace at IIT Bombay
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Title |
Effect of Pre-straining on the Shape Recovery of Fe-Mn-Si-Cr-Ni Shape Memory Alloys
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Creator |
MAJI, BC
KRISHNAN, M VERMA, A BASU, R SAMAJDAR, I RAY, RK |
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Subject |
SIGMA-PHASE PRECIPITATION
STAINLESS-STEEL EPSILON-MARTENSITE SINGLE-CRYSTALS TRANSFORMATION MICROSTRUCTURE TEMPERATURE DEFORMATION COMPRESSION TENSION |
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Description |
The effect of pre-straining on the shape recovery behavior of Fe-14Mn-6Si-9Cr-5Ni (wt pct) shape memory alloy (SMA) has been studied. The shape recovery associated with the reverse epsilon martensitic transformation, i.e., epsilon -> gamma, was characterized by dilatometry using specimens which were pre-strained to different extent (0 to 14 pct). Dilatometric studies revealed that in Fe-Mn-Si-Cr-Ni SMA, the shape recovery takes place in two stages: (i) in the first stage, the unpinned fraction of stress-induced epsilon martensite reverts back to parent phase gamma in the temperature regime of 353 K to 653 K (80 A degrees C to 380 A degrees C) and (ii) in the second stage the remaining "pinned" epsilon martensite is unpinned by the decomposition of deformation-induced alpha' martensite in the temperature range of 743 K to 893 K (470 A degrees C to 620 A degrees C). The amount of recovery in the first stage decreases with pre-strain, whereas it increases in the second stage. The epsilon -> gamma transformation finish temperature, A (f), increases with increase in pre-strain amount, though the reverse transformation start temperature, A (S), remains unaffected. Microstructural characterization revealed that the amount of deformation-induced alpha' martensite depends on the mode of straining and the crystallographic texture of the starting material. The reversion of alpha' martensite is seen to occur by the precipitation of Fe5Ni3Si2-type intermetallic pi-phase within these plates.
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Publisher |
SPRINGER
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Date |
2016-01-14T12:20:04Z
2016-01-14T12:20:04Z 2015 |
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Type |
Article
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Identifier |
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, 46A(2)639-655
1073-5623 1543-1940 http://dx.doi.org/10.1007/s11661-014-2645-y http://dspace.library.iitb.ac.in/jspui/handle/100/17481 |
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Language |
en
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