scholarly journals Study of Co-Ni-Al Alloys with Magnetically Controlled Shape Memory Effect

2009 ◽  
Vol 635 ◽  
pp. 75-80 ◽  
Author(s):  
Irina I. Kositsyna ◽  
V.A. Zavalishin
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Martensite Transformation ◽  
Melt Spinning ◽  
Al Alloys ◽  
Helium Atmosphere ◽  
Melt Spun ◽  
Transformation Hysteresis ◽  
Start Temperature

The methods of electron microscopy, resistometry and magnetometry are used to study ten (36-38)Co - (32-36)Ni - (27-30)Al (at. %) alloys. Cast coarse-crystalline and microcrystalline alloys made by melt spinning in a helium atmosphere are considered. It is shown that the martensite start temperature Ms becomes 30-50°C lower as grains are refined to 1 m m. Replacement of 1 at. % cobalt by nickel and 1 at. % aluminum by nickel makes the temperature interval of the В2«L10 martensite transformation (30-60)°C and (100-110)°C higher respectively. The martensite transformation hysteresis is about 100 degrees. The melt-spun Co38Ni34Al28 alloy with the transformation temperatures Мs = 31°С, Мf = –34°С, Аs = –6°С, Аf = 70°С and Тс = 98°С is a material possessing the magnetically controlled shape memory effect.

The Shape Memory Effect in Melt Spun Fe-15Mn-5Si-9Cr-5Ni Alloys

2013 ◽  
Vol 738-739 ◽  
pp. 247-251 ◽  
Author(s):  
Ana Druker ◽  
Paulo La Roca ◽  
Philippe Vermaut ◽  
Patrick Ochim ◽  
Jorge Malarría
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Melt Spinning ◽  
Room Temperature ◽  
Tensile Tests ◽  
Argon Atmosphere ◽  
Austenitic Phase ◽  
Melt Spun ◽  
Shape Memory Behaviour

At room temperature, Fe-15Mn-5Si-9Cr-5Ni alloys are usually austenitic and the application of a stress induces a reversible martensitic transformation leading to a shape memory effect (SME). However, when a ribbon of this material is obtained by melt-spinning, the rapid solidification stabilizes a high-temperature ferritic phase. The goals of this work were to find the appropriate heat treatment in order to recover the equilibrium austenitic phase, characterize the ribbon form of this material and evaluate its shape memory behaviour. We found that annealing at 1050°C for 60 min, under a protective argon atmosphere, followed by a water quenching stabilizes the austenite to room temperature. The yield stress, measured by tensile tests, is 250 MPa. Shape-memory tests show that a strain recovery of 55% can be obtained, which is enough for certain applications.

Microstructural Features and Shape-Memory Characteristics of Melt-Spun Ni-Al-Fe-B Ribbons

1991 ◽  
Vol 246 ◽  
Author(s):  
C. T. Liu ◽  
C. J. Sparks ◽  
J. A. Horton ◽  
E. P. George ◽  
C. A. Carmichael ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Melt Spinning ◽  
Room Temperature ◽  
Alloy Composition ◽  
X Ray ◽  
Melt Spun ◽  
Bend Angles ◽  
Memory Characteristics

AbstractThis paper summarizes our recent study of NiAI+Fe+B alloy ribbons containing 4 to 20% Fe and doped with 300 wt ppm B. Alloy ribbons were successfully fabricated by rapid solidification via melt spinning. The alloys with 8% Fe and 34% Al-equivalent [=Al%+(Fe%)/2] showed the best bend ductility at room temperature. The ribbons exhibited a reversible martensite (body-centered orthorombic structure) to B2 transformation as evidenced by DSC, X-ray and TEM studies. The shape-memory effect, as characterized by measuring the recovery of bend angles with temperature, is sensitive to alloy composition, with the best recovery observed in SMA-15 (B-doped Ni-27% Al-14% Fe). Annealing at 600°C causes aging embrittlement; in particular, in alloys containing 12% Fe.

Transformation hysteresis and shape memory effect of an ultrafine-grained TiNiNb shape memory alloy

2014 ◽  
Vol 54 ◽  
pp. 133-135 ◽  
Author(s):  
P.C. Jiang ◽  
Y.F. Zheng ◽  
Y.X. Tong ◽  
F. Chen ◽  
B. Tian ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Ultrafine Grained ◽  
Transformation Hysteresis

scholarly journals Shape Memory Effect Associated with FCC—HCP Martensitic Transformation in Co-Al Alloys

2003 ◽  
Vol 44 (12) ◽  
pp. 2732-2735 ◽  
Author(s):  
Toshihiro Omori ◽  
Yuji Sutou ◽  
Katsunari Oikawa ◽  
Ryosuke Kainuma ◽  
Kiyohito Ishida
Keyword(s):  
Martensitic Transformation ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Al Alloys

Magnetic properties of Cu–Mn–Al alloys with shape memory effect

1998 ◽  
Vol 46 (1) ◽  
pp. 137-147 ◽  
Author(s):  
M.O. Prado ◽  
F.C. Lovey ◽  
L. Civale
Keyword(s):  
Magnetic Properties ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Al Alloys

scholarly journals Design of Ethylene-Vinyl Acetate Copolymer Fiber with Two-Way Shape Memory Effect

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1599 ◽  
Author(s):  
Xiaoming Qi ◽  
Wentong Yang ◽  
Laiming Yu ◽  
Wenjun Wang ◽  
Haohao Lu ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Vinyl Acetate ◽  
Memory Effect ◽  
Crosslink Density ◽  
Melt Spinning ◽  
Uv Curing ◽  
Ethylene Vinyl Acetate ◽  
Acetate Copolymer ◽  
Ethylene Vinyl Acetate Copolymer

One-dimensional shape memory polymer fibers (SMPFs) have obvious advantages in mechanical properties, dispersion properties, and weavability. In this work, a method for fabricating semi-crystallization ethylene-vinyl acetate copolymer (EVA) fiber with two-way shape memory effect by melt spinning and ultraviolet (UV) curing was developed. Here, the effect of crosslink density on its performance was systematically analyzed by gel fraction measurement, tensile tests, DSC, and TMA analysis. The results showed that the crosslink density and shape memory properties of EVA fiber could be facilely adjusted by controlling UV curing time. The resulting EVA fiber with cylindrical structure had a diameter of 261.86 ± 13.07 μm, and its mechanical strength and elongation at break were 64.46 MPa and 114.33%, respectively. The critical impact of the crosslink density and applied constant stress on the two-way shape memory effect were analyzed. Moreover, the single EVA fiber could lift more than 143 times its own weight and achieve 9% reversible actuation strain. The reversible actuation capability was significantly enhanced by a simple winding design of the single EVA fiber, which provided great potential applications in smart textiles, flexible actuators, and artificial muscles.

Magnetic property and shape memory effect of melt spun Fe-Mn-Cr-Si-Nd-B ribbons

2007 ◽  
Vol 25 (1-4) ◽  
pp. 55-59 ◽  
Author(s):  
Takashi Todaka ◽  
Teruo Yasuoka ◽  
Masato Enokizono ◽  
Kenji Tsutsumi ◽  
Roland Groessinger ◽  
...  
Keyword(s):  
Magnetic Property ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Melt Spun

scholarly journals Shape Memory Effect in an Ordered Fe3Pt Alloy Associated with the FCC-FCT Thermoelastic Martensite Transformation

1985 ◽  
Vol 26 (7) ◽  
pp. 523-524 ◽  
Author(s):  
Ryuichiro Oshima ◽  
Seiji Sugimoto ◽  
Masaaki Sugiyama ◽  
Tokio Hamada ◽  
Francisco Eiichi Fujita
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Martensite Transformation ◽  
Pt Alloy
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