Boron-rich Ni-B-C amorphous alloys prepared by rapid quenching

1986 ◽  
Vol 5 (11) ◽  
pp. 1178-1180 ◽  
Author(s):  
A. Inoue ◽  
T. Nakamura ◽  
T. Masumoto
Keyword(s):  
Amorphous Alloys ◽  
Rapid Quenching

Bulk Metallic Glasses

2008 ◽  
Vol 604-605 ◽  
pp. 229-238
Author(s):  
Marcello Baricco ◽  
Tanya A. Başer ◽  
Gianluca Fiore ◽  
Rafael Piccin ◽  
Marta Satta ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Metallic Glasses ◽  
Amorphous Alloys ◽  
Shear Bands ◽  
Bulk Metallic Glasses ◽  
Rapid Quenching ◽  
Second Phase ◽  
Research Activity ◽  
Long Time ◽  
Geometrical Constraints

Rapid quenching techniques have been successfully applied since long time for the preparation of metallic glasses in ribbon form. Only in the recent years, the research activity addressed towards the synthesis of bulk metallic glasses (BMG), in form of ingots with a few millimetres in thickness. These materials can be obtained by casting techniques only for selected alloy compositions, characterised by a particularly high glass-forming tendency. Bulk amorphous alloys are characterised by a low modulus of elasticity and high yielding stress. The usual idea is that amorphous alloys undergo work softening and that deformation is concentrated in shear bands, which might be subjected to geometrical constraints, resulting in a substantial increase in hardness and wear resistance. The mechanical properties can be further improved by crystallisation. In fact, shear bands movement can be contrasted by incorporating a second phase in the material, which may be produced directly by controlled crystallisation. Soft magnetic properties have been obtained in Fe-based systems and they are strongly related to small variations in the microstructure, ranging from a fully amorphous phase to nanocrystalline phases with different crystal size. The high thermal stability of bulk metallic glasses makes possible the compression and shaping processes in the temperature range between glass transition and crystallisation. Aim of this paper is to present recent results on glass formation and properties of bulk metallic glasses with various compositions. Examples will be reported on Zr, Fe, Mg and Pd-based materials, focussing on mechanical and magnetic properties.

scholarly journals Giant Stress Impedance Magnetoelastic Sensors Employing Soft Magnetic Amorphous Ribbons

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2175 ◽  
Author(s):  
Juan Jesús Beato-López ◽  
Juan Garikoitz Urdániz-Villanueva ◽  
José Ignacio Pérez-Landazábal ◽  
Cristina Gómez-Polo
Keyword(s):  
Amorphous Alloys ◽  
Subsequent Development ◽  
Young Modulus ◽  
Amorphous Structure ◽  
Rapid Quenching ◽  
Soft Magnetic ◽  
Highly Sensitive ◽  
Magnetoelastic Sensors ◽  
Soft Magnetic Amorphous Alloys

Soft magnetic amorphous alloys obtained via rapid quenching techniques are widely employed in different technological fields such as magnetic field detection, bio labeling, non-contact positioning, etc. Among them, magnetoelastic applications stand out due to excellent mechanical properties exhibited by these alloys, resulting from their amorphous structure, namely, their high Young modulus and high tensile strength. In particular, the giant stress impedance (GSI) effect represents a powerful tool to develop highly sensitive magnetoelastic sensors. This effect is based on the changes in the high-frequency electric impedance as the result of the variation in magnetic permeability of the sample under the action of mechanical stresses. In this work, the GSI effect is analyzed in two soft magnetic ribbons ((Co0.93 Fe0.07)75 Si12.5 B12.5 and (Co0.95 Fe0.05)75 Si12.5 B12.5) for the subsequent development of two practical devices: (i) the characterization of the variations in the cross-section dimensions of irregularly shaped elements, and (ii) the design of a flow meter for measuring the rate of flow of water through a pipe.

Effect of Electron Irradiation on Nanocrystallization of Fe-Nd-B Amorphous Alloys

2006 ◽  
Vol 512 ◽  
pp. 107-110 ◽  
Author(s):  
Akihiro Nino ◽  
Takeshi Nagase ◽  
Yukichi Umakoshi
Keyword(s):  
Grain Size ◽  
Amorphous Phase ◽  
Electron Irradiation ◽  
Amorphous Alloys ◽  
Single Phase ◽  
Nanocrystalline Structure ◽  
Rapid Quenching ◽  
Thermal Crystallization ◽  
Average Grain Size ◽  
Induced Crystallization

Formation of a nanocrystalline structure through rapid solidification, thermal crystallization and electron irradiation induced crystallization was investigated in Fe-Nd-B alloys. A nanocrystalline structure was obtained by rapid quenching of the melt in a Fe86Nd9B5 alloy, while an amorphous single phase was formed in a Fe77Nd4.5B18.5 alloy. In the latter alloy, a nanocrystalline structure was obtained by thermal crystallization and electron irradiation induced crystallization of the amorphous phase. The average grain size of the precipitate obtained by irradiation at 298 K was about 8 nm, which is much smaller than that obtained during thermal crystallization. Results indicate that electron irradiation is effective for obtaining a novel nanocrystalline structure in Fe-Nd-B alloys.

Molecular-Dynamic Computer Simulation Study of Structural and Transport Properties of Some Amorphous Alloys

1991 ◽  
Vol 02 (01) ◽  
pp. 523-526 ◽  
Author(s):  
O.S. TRUSHIN ◽  
P. NAYAK ◽  
V.S. STEPANYUK ◽  
A.A. KATSNELSON ◽  
A. SZASZ
Keyword(s):  
Computer Simulation ◽  
Amorphous Alloys ◽  
Pair Correlation ◽  
Amorphous State ◽  
Rapid Quenching ◽  
Atomic Level ◽  
Dynamic Phase ◽  
Fast Cooling ◽  
Dynamic Computer Simulation ◽  
Molecular Dynamic Computer Simulation

Here we present the molecular-dynamics computer simulation for a few systems of Ni1−xPx (x=0.2,0.25), Fe1−xPx (x=0.24), and Fe1−xBx (x=0.15) to explore the dynamic phase transformation from liquid to amorphous state through rapid quenching and the structure of these alloys at atomic level. The truncated Morse potential has been used to model the interaction between the atoms. The results of computer simulation for the pair correlation function for these systems reveal some interesting features of the corresponding alloy going from the melt to amorphous state through fast cooling. Finally the analysis of Voronoy polyhedron statistic leads us to propose possible models for the structure at atomic level for these alloys in the amorphous state. For the Ni75P25 system it is also revealed that the metastable state depends on the method of preparation of the sample.

scholarly journals Influence of Annealing on the Microstructure and Magnetic Properties in Amorphous Alloys

2014 ◽  
Vol 59 (2) ◽  
pp. 663-666 ◽  
Author(s):  
P. Pietrusiewicz ◽  
M. Nabiałek ◽  
M. Szota ◽  
M. Dośpiał ◽  
K. Błoch ◽  
...  
Keyword(s):  
Amorphous Alloys ◽  
Rapid Quenching ◽  
Structural Defects ◽  
X Ray Diffraction ◽  
Second Stage ◽  
Linear Defects ◽  
Crystallisation Temperature ◽  
Type Size ◽  
Magnetisation Curve ◽  
Microstructure And Magnetic Properties

Abstract The influence of isothermal annealing on the magnetisation process in strong magnetic fields of the amorphous Fe61Co10Y8Ni1B20 alloy ribbons was investigated. Samples in the form of ribbons were produced by rapid quenching of liquid alloy on a rotating copper wheel. In order to study the relaxation process, the investigated Fe61Co10Y8Ni1B20 samples were subjected to annealing below the crystallisation temperature at 700 K for 1 h and then at 770 K for 3.5 h. The structure of the samples was examined by X-ray diffraction measurements (XRD). It was found, that all of measured samples in the as-cast state and after thermal treatment, were amorphous. On the basis of virgin magnetisation curve analysis, the type, size and density of structural defects occurring in the investigated samples were determined. It was found that after the first stage of annealing, decay of linear defects (pseudo-dislocation dipoles) into smaller, more thermodynamically stable, point defects occurs. The presence of point like defects was also confirmed after the second stage of annealing.

scholarly journals Crystallization of Fe-Based Bulk Amorphous Alloys

2015 ◽  
Vol 60 (1) ◽  
pp. 7-10 ◽  
Author(s):  
K. Błoch ◽  
M. Nabiałek ◽  
M. Dośpiał ◽  
S. Garus
Keyword(s):  
Amorphous Alloys ◽  
Rapid Quenching ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
Two Stages ◽  
Two Peaks ◽  
Structure Investigations ◽  
Dsc Curves

Abstract The aim of this paper is to present the results of crystallization studies for the bulk amorphous (Fe0.61Co0.10Zr0.025Hf0.025 Ti0.02W0.02B0.20)98Y2, Fe61Co10TixY6B20, Fe61Co10Ti2Y7B20 alloys. The crystallization of the alloys was studied by differential scanning calorimetry (DSC). The amorphicity of the investigated alloys in the as-quenched state was testified using Mossbauer spectroscopy, X-ray diffractometry and transmission electron microscopy. Moreover, X-ray diffractometry was applied to structure investigations of partially crystallized samples. The crystallization process in the investigated alloys occurs in one or two stages. Two peaks in the DSC curves can be overlapped or well separated indicating the complex crystallization processes. From X-ray diffraction we have stated that in both types of devitrification the crystalline phase can be ascribed to the α-FeCo. In the first stage the crystalline grains seem to grow from the nuclei frozen in the samples during the rapid quenching, whereas in the second one both the growth of the existed grains and creation of new ones during annealing may occur.

scholarly journals 11B NMR STUDY OF AMORPHOUS ALLOYS Fe85-xCrxB15 (x = 0-20)

2019 ◽  
Vol 484 (6) ◽  
pp. 678-681
Author(s):  
V. S. Pokatilov ◽  
A. S. Sigov ◽  
A. O. Makarova ◽  
E. F. Pevtsov
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Amorphous Alloys ◽  
Short Range ◽  
Short Range Order ◽  
Chromium Content ◽  
Magnetic Moments ◽  
Rapid Quenching ◽  
Nmr Study ◽  
11B Nmr ◽  
Pulsed Nuclear Magnetic Resonance

Amorphous alloys Fe85-xCrxB15 (x = 0-20), prepared by rapid quenching of the melt, have been studied by pulsed nuclear magnetic resonance (NMR) on nuclei 11B at a temperature of 4,2 K. The amorphous alloys consist of nanoclusters with short-range order of the tetragonal t-(Fe, Cr)3B and α-(Fe, Cr) phases which contain chromium atoms in the nearest surroundings of boron atoms. The average magnetic moments of magnetic atoms in the nearest sphere of boron atoms in nanoclusters and their dependence on the chromium content in alloys are estimated.

scholarly journals Magnetocaloric effect of Co62Nb6Zr2B30 amorphous alloys obtained by mechanical alloying or rapid quenching

2014 ◽  
Vol 115 (17) ◽  
pp. 17A302 ◽  
Author(s):  
L. M. Moreno ◽  
J. S. Blázquez ◽  
J. J. Ipus ◽  
J. M. Borrego ◽  
V. Franco ◽  
...  
Keyword(s):  
Mechanical Alloying ◽  
Magnetocaloric Effect ◽  
Amorphous Alloys ◽  
Rapid Quenching
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