The Effect of Quenching Variables on the Transformation Characteristics of Some Rsp Shape-Memory Alloys

1983 ◽  
Vol 28 ◽  
Author(s):  
J.V. Wood
Keyword(s):  
Shape Memory ◽  
Vacancy Concentration ◽  
Process Variable ◽  
Excess Vacancy ◽  
Large Excess ◽  
Quenching Rate ◽  
Planar Flow Casting ◽  
Predominant Process ◽  
Rapidly Solidified ◽  
Wheel Material

ABSTRACTRibbons of a Cu-Al-Ni shape memory alloy have been rapidly solidified by planar flow casting. Attempts have been made to vary casting and secondary quench conditions in order to identify the predominant process variable in determining the subsequent β1↔γ1′ transformation temperatures. By varying wheel speed, wheel material and secondary quenching rate it is concluded that the large excess vacancy concentration has most influence on the as cast ribbon, but that after subsequent heat treatment, the grain size dominates.

Shape memory properties and microstructural evolution of rapidly solidified CuAlBe alloys

2013 ◽  
Vol 80 ◽  
pp. 92-97 ◽  
Author(s):  
Semra Ergen ◽  
Orhan Uzun ◽  
Fikret Yilmaz ◽  
M. Fatih Kiliçaslan
Keyword(s):  
Shape Memory ◽  
Microstructural Evolution ◽  
Shape Memory Properties ◽  
Rapidly Solidified

X-ray and Mössbauer study of rapidly solidified Ce20Fe80 ribbons; effect of the quenching rate

1994 ◽  
Vol 88 (1) ◽  
pp. 65-71 ◽  
Author(s):  
G. Roulin ◽  
J. Teillet ◽  
A. Fnidiki ◽  
B. Labulle ◽  
P. Ochin
Keyword(s):  
Mössbauer Study ◽  
Quenching Rate ◽  
X Ray ◽  
Rapidly Solidified

Characterization of Reversibly-Actuating Shape Memory Alloy Foils Produced By Planar Flow Casting

2021 ◽  
Author(s):  
Ling Chen ◽  
David Renshaw ◽  
Michael Kellam ◽  
Ritaban Dutta ◽  
Daniel Liang
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Planar Flow ◽  
Planar Flow Casting

scholarly journals Fabrication and Shape Memory Characteristics of Highly Porous Ti-Nb-Mo Biomaterials

2017 ◽  
Vol 62 (2) ◽  
pp. 1367-1370 ◽  
Author(s):  
Y.-W. Kim ◽  
T.W. Mukarati
Keyword(s):  
Martensitic Transformation ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Differential Scanning Calorimetric ◽  
Porous Scaffolds ◽  
High Porosity ◽  
Porous Ti ◽  
Human Body Temperature ◽  
Rapidly Solidified

AbstractNon-toxic Ti-Nb-Mo scaffolds were fabricated by sintering rapidly solidified alloy fibers for biomedical applications. Microstructure and martensitic transformation behaviors of the porous scaffolds were investigated by means of differential scanning calorimetric and X-ray diffraction. Theα″–βtransformation occurs in the as-solidified fiber and the sintered scaffolds. According to the compressive test of the sintered scaffolds with 75% porosity, they exhibit good superelasticity and strain recovery ascribed to the stress-induced martensitic transformation and the shape memory effect. Because of the high porosity of the scaffolds, an elastic modulus of 1.4 GPa, which matches well with that of cancellous bone, could be obtained. The austenite transformation finishing temperature of 77Ti-18Nb-5Mo alloy scaffolds is 5.1°C which is well below the human body temperature, and then all mechanical properties and shape memory effect of the porous 77Ti-18Nb-5Mo scaffolds are applicable for bon replacement implants.

Microstructure of Nb3 (AlSiB) superconducting tapes with extremely high critical current densities

1989 ◽  
Vol 4 (3) ◽  
pp. 526-529 ◽  
Author(s):  
Mireille Treuil Clapp ◽  
Zhang Jian ◽  
Tariq Manzur
Keyword(s):  
Critical Current ◽  
Melt Spinning ◽  
Quenching Rate ◽  
Fine Grained ◽  
Annealing Conditions ◽  
Second Phases ◽  
Current Densities ◽  
Rapidly Solidified ◽  
Equiaxed Grains ◽  
A15 Phase

Alloys of Nb73Al12Si14.5B0.5 were rapidly solidified into amorphous ribbons using the melt spinning technique. These were isothermally annealed at temperatures ranging from 660 to 780 °C. The A15 phase began to crystallize at 700 °C and small amounts of second phases appeared at the higher temperatures. Crystallization was dependent on quenching rate as well as annealing conditions. Below 750 °C nucleation was nonuniform and was enhanced by surfaces and quenched-in nuclei. Above 750 °C nucleation became more uniform and completely crystalline ribbons with equiaxed grains ∼30 nm in diameter were obtained. These ultra fine grained ribbons had extremely high superconducting critical current densities of 8 × 1010 A/m2 and 5 × 1010 A/m2 at magnetic fields of 0.5 and 15 tesla, respectively, at 4.2 K.

scholarly journals Effect of Heat Treatment Temperature on Martensitic Transformation and Superelasticity of the Ti49Ni51 Shape Memory Alloy

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2539 ◽  
Author(s):  
Peiyou Li ◽  
Yongshan Wang ◽  
Fanying Meng ◽  
Le Cao ◽  
Zhirong He
Keyword(s):  
Heat Treatment ◽  
Martensitic Transformation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Thermal Hysteresis ◽  
Treatment Temperature ◽  
Heat Treated ◽  
Different Temperatures ◽  
Tini Phase ◽  
Rapidly Solidified

The martensitic transformation and superelasticity of Ti49Ni51 shape memory alloy heat-treatment at different temperatures were investigated. The experimental results show that the microstructures of as-cast and heat-treated (723 K) Ni-rich Ti49Ni51 samples prepared by rapidly-solidified technology are composed of B2 TiNi phase, and Ti3Ni4 and Ti2Ni phases; the microstructures of heat-treated Ti49Ni51 samples at 773 and 823 K are composed of B2 TiNi phase, and of B2 TiNi and Ti2Ni phases, respectively. The martensitic transformation of as-cast Ti49Ni51 alloy is three-stage, A→R→M1 and R→M2 transformation during cooling, and two-stage, M→R→A transformation during heating. The transformations of the heat-treated Ti49Ni51 samples at 723 and 823 K are the A↔R↔M/A↔M transformation during cooling/heating, respectively. For the heat-treated alloy at 773 K, the transformations are the A→R/M→R→A during cooling/heating, respectively. For the heat-treated alloy at 773 K, only a small thermal hysteresis is suitable for sensor devices. The stable σmax values of 723 and 773 K heat-treated samples with a large Wd value exhibit high safety in application. The 773 and 823 K heat-treated samples have large stable strain–energy densities, and are a good superelastic alloy. The experimental data obtained provide a valuable reference for the industrial application of rapidly-solidified casting and heat-treated Ti49Ni51 alloy.

scholarly journals Two-Way Shape Memory Effect and Micromachine of Rapidly Solidified Ferromagnetic Fe–Pd Ribbon

2006 ◽  
Vol 47 (3) ◽  
pp. 615-618 ◽  
Author(s):  
Harunobu Tomita ◽  
Teiko Okazaki ◽  
Yasubumi Furuya
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Rapidly Solidified
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