Field heat treatment of ferromagnetic metallic glasses

1975 ◽  
Vol 26 (7) ◽  
pp. 405-406 ◽  
Author(s):  
H. S. Chen ◽  
S. D. Ferris ◽  
E. M. Gyorgy ◽  
H. J. Leamy ◽  
R. C. Sherwood
Keyword(s):  
Heat Treatment ◽  
Metallic Glasses

Exoelectron emission from unexcited metallic glasses Fe78B13Si9 during heat treatment

1992 ◽  
Vol 7 (6) ◽  
pp. 1396-1399 ◽  
Author(s):  
Yoshihisa Watanabe ◽  
Tadayoshi Kubozoe ◽  
Yoshikazu Nakamura
Keyword(s):  
Heat Treatment ◽  
Metallic Glasses ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Exoelectron Emission ◽  
Radiation Chemical ◽  
Temperature Range ◽  
High Vacuum Condition ◽  
Before And After ◽  
Ultra High Vacuum Condition

Exoelectron emission from the surface of unexcited metallic glasses Fe78B13Si9 during heat treatment has been studied under ultra high vacuum condition. In the first heating cycle, exoelectrons are emitted from the as-cast ribbon in the temperature range from approximately 423 K to 773 K (150 °C to 500 °C), although the surface of the specimen is not excited by ionizing radiation, chemical processes, or mechanical treatments prior to measurements. In the second and subsequent heating cycles, however, there is no anomalous emission observed in the same temperature range. In order to elucidate the mechanism of emission, the surface of the specimen is observed by the atomic force microscope (AFM) before and after measurements. In the AFM image, many crystallites in the amorphous matrix can be found in the surface of the heated specimen. These experimental results show that exoelectrons are emitted in the same temperature range as the early stages of crystallization on the surface of metallic glasses. We hypothesize that the two effects are correlated.

Structural changes and physical properties of Fe–Ni-based metallic glasses rapidly heated by pulsed electrical currents

1991 ◽  
Vol 6 (5) ◽  
pp. 1028-1034 ◽  
Author(s):  
L. Zaluski ◽  
A. Zaluska ◽  
M. Kopcewicz ◽  
R. Schulz
Keyword(s):  
Heat Treatment ◽  
Magnetic Properties ◽  
Metallic Glasses ◽  
Structural Changes ◽  
Annealing Treatment ◽  
Electrical Current ◽  
Liquid Nitrogen Temperature ◽  
Alpha Phase ◽  
Thermal Spike ◽  
Electrical Currents

Fe–Ni–Si–B metallic glasses have been annealed and crystallized using short electrical current pulses. Two types of electrical heat treatment have been used. The first one is an isothermal annealing treatment using a very high initial heating rate while the second one is a thermal spike applied on an amorphous sample held at various initial temperatures. The microstructure of the alloys after heat treatment has been characterized by x-ray diffraction, transmission electron microscopy, and Mössbauer spectroscopy. The thermal and magnetic properties of the samples measured by DSC and hysteresis loop tracer have been studied after the various heat treatments and correlated with the microstructure of the alloys. The crystallization at high temperatures produces the gamma phase only, while at low temperatures, a mixture of the gamma and alpha phases (the alpha phase being predominant) is usually observed. The samples initially held at liquid nitrogen temperature and heat treated with a thermal spike remain amorphous and show improved magnetic properties (lower coercive field and higher induction at saturation) without loss of ductility.

Synthesis and Magnetic Properties of Nanocomposite Magnets Self-Organized from FeB-Nd-Nb Metallic Glasses

2008 ◽  
Vol 1118 ◽  
Author(s):  
R Tamura ◽  
S Kobayashi ◽  
T Fukuzaki ◽  
M Kamiko
Keyword(s):  
Heat Treatment ◽  
Metallic Glasses ◽  
Treatment Condition ◽  
Heat Treatment Condition ◽  
The Self ◽  
Quenching Rate ◽  
Glass Forming ◽  
Self Organized ◽  
Nanocomposite Magnets ◽  
Treatment Conditions

ABSTRCTChange of the magnetic property of Fe-B-Nd-Nb alloys was investigated with replacing Nb by a glass forming element Zr under constant quenching rate as well as heat treatment conditions. As a result, the coercivity significantly increases up to 1207 kA/m when the half of Nd is replaced by Zr, which is presumably due to grain refinement of the Nd2Fe14B phase. The self-organized nanograin magnets are attractive for future applications since their coercivity can be further improved by reducing the grain size via optimizing the Zr concentration, the quenching rate and the subsequent heat treatment condition.

Corrosion Resistance Of fe- and Ni- Based Metallic Glasses

1983 ◽  
Vol 28 ◽  
Author(s):  
B.-O. Reinders ◽  
H. W. Bergmann
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Metallic Glasses ◽  
High Temperature Oxidation ◽  
Ph Value ◽  
Corrosion Behaviour ◽  
Oxidation Behaviour ◽  
Electrolyte Temperature ◽  
Temperature Oxidation

ABSTRACTThe corrosion behaviour in liquid electrolytes were investigated for some Fe- and Ni-based metallic glasses varying pH-value, electrolyte temperature and heat treatment. For some (Fe100-xMx)83B17 glasses the high temperature oxidation behaviour was studied.

scholarly journals Extra plasticity governed by shear band deflection in gradient metallic glasses

2021 ◽  
Author(s):  
Yao Tang ◽  
Haofei Zhou ◽  
Xiaodong Wang ◽  
Qingping Cao ◽  
Dongxian Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Metallic Glasses ◽  
Atomistic Simulations ◽  
Spatial Gradient ◽  
Metallic Materials ◽  
Bulk Materials ◽  
Gradient Materials ◽  
Ultrahigh Strength ◽  
Significant Research

Abstract Inspired by gradient materials in nature, advanced engineering components with controlled structural gradients have attracted significant research interest due to their exceptional combinations of properties. However, it remains challenging to generate structural gradients that penetrate through bulk materials, which is essential for achieving enhanced mechanical properties in metallic materials. Here, we propose a heat treatment engineering protocol to realize a controllable structural gradient in bulk metallic glasses (BMGs). By adjusting the holding time of cryogenic thermal cycling, a series of BMGs with gradient-distributed free volume contents from internal to external can be synthesized. Both mechanical testing and atomistic simulations demonstrate that the spatial gradient can endow BMGs with extra plasticity without sacrificing their ultrahigh strength. Such an enhanced mechanical property is governed by the gradient-induced deflection of shear deformation that fundamentally suppresses the unlimited shear localization on a straight plane that would be expected in BMGs without such a gradient.

The Effects of Annealing on Fatigue Behavior in Zr-based Bulk Metallic Glasses

2011 ◽  
Vol 1300 ◽  
Author(s):  
Peng Tong ◽  
Despina Louca ◽  
Yoshihiko Yokoyama ◽  
Anna Llobet ◽  
Gongyao Wang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Metallic Glasses ◽  
Local Structure ◽  
Structural Changes ◽  
Fatigue Behavior ◽  
Bulk Metallic Glasses ◽  
Fatigue Loading ◽  
Annealed Sample ◽  
Loading Conditions ◽  
Pair Density

ABSTRACTThe effects of annealing and fatigue on the local structure of Zr50Cu40Al10 and Zr60Cu30Al10 bulk metallic glasses (BMG) were investigated using the pair density function (PDF) analysis of synchrotron X-ray and neutron diffraction data. Our results indicate that the two compositions respond differently to annealing. The first PDF peak becomes sharper after annealing in Zr50Cu40Al10 with its intensity increasing, indicating that short-range ordering may be induced after the heat treatment. On the other hand, in Zr60Cu30Al10, the effects due to the heat treatment on the local structure are more subtle. Separately, the as-quenched and annealed alloys with the composition Zr50Cu40Al10 were subjected to fatigue loading conditions with ~ 106 compression cycles. The room temperature measurements showed changes in the local structure with fatigue especially for the annealed sample, involving the Cu-Zr correlations. Our results suggest that the physical properties of BMGs upon fatigue loading conditions may become accentuated due to the structural relaxation brought upon by annealing, leading to observable structural changes at the atomic level from fatigue.

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