The effect of rapid solidification and grain size on the transformation temperatures of Ni-44,8wt%Ti melt spun alloy

2012 ◽  
Vol 1373 ◽  
Author(s):  
G. C. S. Anselmo ◽  
W. B. de Castro ◽  
C. J. de Araújo
Keyword(s):  
Differential Scanning Calorimetry ◽  
Grain Size ◽  
Martensitic Transformation ◽  
Rapid Solidification ◽  
Melt Spinning ◽  
Scanning Calorimetry ◽  
Transformation Temperatures ◽  
Melt Spun ◽  
Melt Spun Ribbons ◽  
Melt Spinning Technique

ABSTRACTRibbons of the Ni-44.8wt%Ti shape memory alloy are prepared through the melt spinning technique. The study is focused on investigating the effect of the rapid solidification and grain size at characteristic start martensitic (Ms), final martensitic (Mf), start austenite (As) and final austenite (Af) transformation temperatures. Changes on martensitic transformation temperatures in Ti45Ni55 melt spun ribbons are observed as grain size is reduced. Results of optical microscopy and differential scanning calorimetry (DSC) are used to associate grain size with transformation temperatures.

Effect of Cooling Rate on the Transformation Temperatures of Ni50Ti36Hf14 Melt-Spun Ribbons

2018 ◽  
Vol 930 ◽  
pp. 345-348
Author(s):  
R.L. Soares ◽  
Walman Benicio Castro
Keyword(s):  
Differential Scanning Calorimetry ◽  
Martensitic Transformation ◽  
Cooling Rate ◽  
Melt Spinning ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Melt Spun ◽  
Melt Spun Ribbons ◽  
Memory Characteristics

Solidification structures and shape memory characteristics of Ni50Ti36Hf14(at.%) alloy ribbons prepared by melt spinning were investigated by means of differential scanning calorimetry and X-ray diffraction. In these experiments particular attention has been paid to change the velocity of cooling wheel from 20 to 40 m/s. Then the cooling rates of ribbons were controlled. The effect of this cooling rate on solidification structures and martensitic transformation behaviors is discussed. When the ribbon is produced at a wheel velocity of 40 m/s in melt spinning, the degree of supercooling becomes high because of its thinner thickness.

Copper-Base Alloys Processed by Rapid Solidification and Ion Implantation

1985 ◽  
Vol 58 ◽  
Author(s):  
J.V. Wood ◽  
C.J. Elvidge ◽  
E. Johnson ◽  
A. Johansen ◽  
L. Sarholt-Kristensen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Martensitic Transformation ◽  
Ion Implantation ◽  
Rapid Solidification ◽  
Melt Spinning ◽  
Scanning Calorimetry ◽  
Copper Base ◽  
Similarities And Differences ◽  
Rapidly Solidified

ABSTRACTAlloys of Cu-Sn and Cu-B have been processed by both melt spinning and ion implantation. In some instances (eg Cu-Sn alloys) rapidly solidified ribbons have been subjected to further implantation. This paper describes the similarities and differences in structure of materials subjected to a dynamic and contained process. For example in Cu-B alloys (up to 2wt% Boron) extended solubility is found in implanted alloys which is not present to the same degree in rapidly solidified alloys of the same composition. Likewise the range and nature of the reversible martensitic transformation is different in both cases as examined by electron microscopy and differential scanning calorimetry.

The effect of rapid solidification and grain size on the transformation temperatures of Cu–Al–Be melt spun alloys

2006 ◽  
Vol 57 (3) ◽  
pp. 154-159 ◽  
Author(s):  
G.A. Lara-Rodriguez ◽  
G. Gonzalez ◽  
H. Flores-Zúñiga ◽  
J. Cortés-Pérez
Keyword(s):  
Grain Size ◽  
Rapid Solidification ◽  
Transformation Temperatures ◽  
Melt Spun

Epitaxial dependence of the melting behavior of In nanoparticles embedded in Al matrices

1997 ◽  
Vol 12 (1) ◽  
pp. 119-123 ◽  
Author(s):  
H. W. Sheng ◽  
G. Ren ◽  
L. M. Peng ◽  
Z. Q. Hu ◽  
K. Lu
Keyword(s):  
Differential Scanning Calorimetry ◽  
Melting Point ◽  
Melting Temperature ◽  
Melt Spinning ◽  
Melting Behavior ◽  
Scanning Calorimetry ◽  
Equilibrium Melting Point ◽  
Milled Sample ◽  
Melt Spun ◽  
Al Matrix

Nanometer-sized In particles (5−45 nm) embedded in the Al matrix were prepared by using melt-spinning and ball-milling techniques. Different crystallographic orientationships between In nanoparticles and the Al matrix were constructed by these two approaches. Melting behavior of the In particles were investigated by means of differential scanning calorimetry (DSC). It was found that the epitaxially oriented In nanoparticles (with the Al matrix) in the melt-spun sample were superheated to about 0−38 °C, whereas the randomly oriented In particles in the ball-milled sample melted below its equilibrium melting point by about 0−22 °C. We suggest that the melting temperature of In nanoparticles can be either enhanced or depressed, depending on the epitaxy between In and the Al matrix.

Study of Two-Way Shape Memory Behavior of Amorphous-Crystalline TiNiCu Melt-Spun Ribbons

2013 ◽  
Vol 738-739 ◽  
pp. 352-356 ◽  
Author(s):  
Alexander Shelyakov ◽  
Nikolay Sitnikov ◽  
Sergey Saakyan ◽  
Alexey Menushenkov ◽  
Razhudin Rizakhanov ◽  
...  
Keyword(s):  
Experimental Data ◽  
Shape Memory ◽  
Martensite Transformation ◽  
Melt Spinning ◽  
Shape Recovery ◽  
Electrochemical Polishing ◽  
Melt Spun ◽  
Melt Spun Ribbons ◽  
The Relationship ◽  
Melt Spinning Technique

Recently we reported on the development of a composite material exhibiting reversible shape memory effect. A Ti–25Ni–25Cu (at.%) alloy was obtained by the melt spinning technique as amorphous–crystalline ribbons with a thickness of approximately 40 μm. The thickness of the amorphous and crystalline layers (dа and dc, respectively) was varied by electrochemical polishing. It has been ascertained that with varying the relationship dc/dа the martensite transformation and shape-recovery temperatures do not actually change, while the minimum radius of the ribbon bending decreases from 8.0 mm to 2.4 mm with increasing the relationship dc/dа from 0.33 to 1.40. The maximum reversible strain comprises 0.4% at dc/dа = 0.82. On the basis of experimental data obtained the phenomenological description, providing an explanation for nature of the phenomena taking place in the rapidly quenched amorphous-crystalline ribbon composite, has been proposed.

Magnetic and Magneto-Optical Research of Ni43.7Mn43.6In12.7 Ribbons

2015 ◽  
Vol 233-234 ◽  
pp. 200-203 ◽  
Author(s):  
Andrey Novikov ◽  
Elena Gan’shina ◽  
Lorena Gonzalez-Legarreta ◽  
V.M. Prida ◽  
Blanca Hernando ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Chemical Composition ◽  
Martensitic Transformation ◽  
Energy Range ◽  
Rapid Solidification ◽  
Kerr Effect ◽  
Melt Spinning ◽  
Spectral Energy ◽  
The Difference ◽  
Melt Spinning Technique

We report the magnetic and magneto-optical (MO) properties of the Heusler Ni43.7Mn43.6In12.7 alloy ribbon in martensitic and austenitic states. The samples were produced by rapid solidification using the melt-spinning technique. The difference between the transformation temperatures obtained from magnetization and transverse Kerr effect (TKE) measurements shows that the chemical composition and/or microstructure are not identical in the bulk and at the ribbon surface. The TKE spectra profile in the spectral energy range of 0.5-3.5 eV does not change significantly at the martensitic transformation that indicates on a very similar electronic structure in martensitic and austenitic states.

Metastable ordered austenite in rapidly solidified Fe-Al-C alloys

1989 ◽  
Vol 47 ◽  
pp. 516-517
Author(s):  
J. A. Sarreal
Keyword(s):  
Rapid Solidification ◽  
Melt Spinning ◽  
X Ray Diffraction ◽  
Austenitic Phase ◽  
X Ray ◽  
Transmission Electron ◽  
Melt Spun ◽  
Melt Spun Ribbons ◽  
Equilibrium Phases ◽  
Rapidly Solidified

Conventionally cast Fe-Al-C alloys are extremely brittle containing combinations of ferrite, carbide and other phases. Rapid solidification has the potential of altering the microstructure to subsequently change the resulting mechanical properties. An apparent conflict exist concerning the effect of rapid solidification on the resulting microstructure of these alloys. Inoue and co-workers, using transmission electron microscopy (TEM) and electron diffraction analyses, reported the presence of several non-equilibrium phases including austenite (fcc - γ) and ordered austenite (Ll2-γ') structures on alloys containing 1.7 to 2.1 C and 6 to 12 Al in weight % (w/o) on melt spun ribbons 30 μm in thickness. Han and Choo, using x-ray diffraction analysis on 30-48 μm thick melt spun ribbons concluded that this ordered fee phase is rather an austenitic phase in which phase decomposition accompanied by sideband phenomenon had occured.Single roller melt spinning technique was used to make ribbons 35-70 μm thick and 0.5-5 mm wide. X-ray diffration analysis showed single phase austenite for samples 2-6 w/o AI and 2 w/o C. Samples with 8-10 w/o AI and 2 w/o C also showed several superlattice lines in addition to the fundamental fcc peaks.

The Effect of Quenching Rate on Structure and Soft Magnetic Properties of High Bs Fe-Based Nanocrystalline Alloys

2013 ◽  
Vol 829 ◽  
pp. 78-81
Author(s):  
Farzad Hosseini-Nasb ◽  
Ali Beitollahi ◽  
Mohammad Kazem Moravvej-Farshi
Keyword(s):  
Grain Size ◽  
Melt Spinning ◽  
Amorphous Matrix ◽  
Wheel Speed ◽  
Soft Magnetic Materials ◽  
Soft Magnetic ◽  
Quenching Rate ◽  
Melt Spun ◽  
Melt Spun Ribbons ◽  
Good Agreement

Recently some nanocrystalline soft magnetic materials containing nanosized α-Fe grains have been obtained by crystallization of amorphous melt-spun ribbons. These structures are nanocomposites in which nanosized grains are distributed within an amorphous matrix. The soft magnetic ribbons composed of Fe80B10Si8Nb1Cu1 alloy were prepared by melt spinning method with different quenching rates (wheel speed of 10, 20 and 40 m/s). The XRD results exhibit an increase in the copper wheel speed (quenching rate) causes the fraction of crystallinity and grain size to decrease. The grain size varies in the range of 20 to 200 nm that is in good agreement with TEM results. The VSM results show that these nanostructured samples exhibit coercivity in the range of 10 to 30 A/m and magnetic saturation in the range of 1.5 to 1.7 T.

Stability and Phase Transformations of Icosahedral Phase in a 41.5Zr41.5Ti17Ni Alloy

2000 ◽  
Vol 15 (4) ◽  
pp. 892-897 ◽  
Author(s):  
S. Yi ◽  
D. H. Kim
Keyword(s):  
Phase I ◽  
Phase Transformations ◽  
Phase Stability ◽  
Melt Spinning ◽  
Annealing Treatment ◽  
Icosahedral Phase ◽  
Melt Spun ◽  
Intermediate States ◽  
Melt Spun Ribbons ◽  
Melt Spinning Technique

Phase stability and transformations of the icosahedral phase (I-phase) in a 41.5Zr41.5Ti17Ni alloy were investigated using melt-spun ribbons and arc-melted bulk samples. A perfect I-phase can be formed directly from liquid through the melt-spinning technique. The I-phase formed in the ribbon is thermodynamically stable and transforms to W-phase, a 1/1 rational approximant above 565 °C. Formation of the perfect I-phase during annealing treatment of the arc-melted sample is very sluggish. Various types of approximants exist as intermediate states for the transformation of crystalline phases to a perfect I-phase.

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