Shape Memory Effect Analysis by X-Ray Diffraction

1989 ◽  
pp. 43-48
Author(s):  
Zbigniew Bojarski ◽  
Henryk Morawiec
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
X Ray Diffraction ◽  
Effect Analysis ◽  
X Ray

Effect of Nb Content on Superelastic Properties of Biomedical Ti–Zr-Based Shape Memory Alloys

2020 ◽  
Vol 12 (9) ◽  
pp. 1394-1398
Author(s):  
Shuanglei Li ◽  
Mi-Seon Choi ◽  
Tae-Hyun Nam
Keyword(s):  
Tensile Test ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
X Ray Diffraction ◽  
X Ray ◽  
Arc Melting ◽  
Nb Content

Ti–18Zr–xNb–2Sn (x = 10, 11, 11.5, 12, 12.5) (at.%) shape memory alloys were fabricated by arc melting then phase constitutions and superelastic properties were investigated by X-ray diffraction (XRD) and tensile test at various temperatures between 178 K and 413 K. Excellent superelasticity was observed in 12.5Nb alloy at temperatures between 258 K and 298 K. Both superelasticity and shape memory effect were observed in 12Nb alloy at temperatures between 233 K and 383 K. Only shape memory effect was observed in 11Nb and 11.5Nb alloys at temperatures between 298 K and 383 K. 12.5Nb and 12Nb alloys consisted of the main β phase and athermal ω. The amount of β phase decreased with increasing Nb content. 10Nb alloy consisted of main α″ martensite and a small amount of β phase. The Ms temperature measured from the Clausius–Clapeyron relationship decreased greatly with increasing Nb content (100 K/at.% Nb) in these Ti–Zr–Nb–Sn alloys.

Phase Constitution, Mechanical Property and Corrosion Resistance of the Ti-Nb Alloys

2006 ◽  
Vol 324-325 ◽  
pp. 655-658 ◽  
Author(s):  
Bao Lai Wang ◽  
Yan Bo Wang ◽  
Yu Feng Zheng
Keyword(s):  
Corrosion Resistance ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Artificial Saliva ◽  
X Ray Diffraction ◽  
Phase Constitution ◽  
Β Phase ◽  
Bending Strain ◽  
35Nb Alloy

Recently, people devote to the development of Ni-free shape memory alloys in order to avoid the Ni-hypersensitivity and toxicity and pursue absolute safety. The shape memory effect and superelasticity have been reported in the biomedical Ti-Nb based alloys. The purpose of this paper is to report the phase constitution, tensile property, shape memory effect and corrosion resistance of the Ti-Nb alloys. The phase constitutions of the Ti-Nb alloys are investigated by means of X-ray diffraction (XRD). The results reveal that β+α′′ phases are presented in the Ti-35Nb alloy and only β phase in the Ti-52Nb alloy at room temperature. The tensile test and bending tests indicate that the Ti-35Nb alloy exhibits shape memory effect. The shape recovery ratio is near to 80% when the bending strain is 4.4% and decreases with the increase of the total bending strain. The corrosion resistance of the Ti-Nb alloys in the Hank's solution and artificial saliva (pH=7.4) at 37 are investigated by OCP, Tafel and anodic polarization methods. The results indicate that the Ti-35Nb alloy has a better corrosion resistance in the artificial saliva and can replace the Ti-Ni alloy in the dental application. In the non-oral condition, the Ti-52Nb alloy may be preferable.

Mechanical and X-RAY Characterisation of the Assisted Two-Way Shape Memory Effect In NiTi

2000 ◽  
Vol 39 (2) ◽  
pp. 217-224 ◽  
Author(s):  
S. Turenne ◽  
S. Prokoshkin ◽  
V. Brailovski ◽  
N. Sacépé
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
X Ray

Magnetic Shape Memory Effect in Ni-Mn-Ga Single Crystal

2016 ◽  
Vol 879 ◽  
pp. 738-743
Author(s):  
Oleg Heczko ◽  
Vít Kopecký ◽  
Jan Drahokoupil ◽  
Marek Vronka ◽  
Oleksiy Perevertov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
High Mobility ◽  
Type I ◽  
X Ray Diffraction ◽  
Magnetic Shape Memory ◽  
Twin Boundaries ◽  
Induced Structure

Magnetic shape memory effect is general name for several effects in which the most visible feature is huge strain induced by magnetic field. Magnetic field-induced structure reorientation (MIR) occurs due to motion of twin boundaries in single phase. As the magnetic field is a relatively weak force compared with mechanical stress, very high mobility of twin boundaries is crucial. Here we study the properties of martensite relevant for this effect using X-ray diffraction, optical and electron microscopy, magnetic observation and mechanical testing. In 10M modulated martensite, two types of mobile twin boundary (type I and type II) are observed with complex layered microstructures consisting of a hierarchy of twinning systems. We search for analogue with non-magnetic Cu-Ni-Al shape memory alloy.

Shape memory effect of laser welded NiTi plates

2015 ◽  
Vol 08 (06) ◽  
pp. 1550069 ◽  
Author(s):  
J. P. Oliveira ◽  
F. M. Braz Fernandes ◽  
N. Schell ◽  
R. M. Miranda
Keyword(s):  
Laser Welding ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Microstructural Analysis ◽  
Industrial Applications ◽  
X Ray Diffraction ◽  
Initial Shape ◽  
Bending Tests ◽  
Remarkable Result

Laser welding is a suitable joining technique for shape memory alloys (SMAs). This paper reports the existence of shape memory effect (SME) on laser welded NiTi joints, subjected to bending tests, and correlates this effect with the microstructural analysis performed with X-ray diffraction (XRD). All welded samples were able to recover their initial shape after bending to 180°, which is a remarkable result for industrial applications of NiTi involving laser welding.

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.

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