Structural relaxation of residual amorphous matrix and modulus oscillation in nanocrystalline FeSiNbCuB ribbons

1999 ◽  
Vol 11 (8) ◽  
pp. 1133-1140 ◽  
Author(s):  
C.H. Shek ◽  
X.D. Hu ◽  
G.M. Lin ◽  
J. Lin
Keyword(s):  
Structural Relaxation ◽  
Amorphous Matrix ◽  
Residual Amorphous Matrix

scholarly journals The precipitation of nanocrystalline structure in the joule heated Fe72Al5Ga2P11C6B4 metallic glasses

2012 ◽  
Vol 48 (2) ◽  
pp. 319-324 ◽  
Author(s):  
N. Mitrovic ◽  
S. Kane ◽  
S. Roth ◽  
A. Kalezic-Glisovic ◽  
C. Mickel ◽  
...  
Keyword(s):  
Metallic Glasses ◽  
Amorphous Alloys ◽  
Amorphous Matrix ◽  
Annealing Treatment ◽  
Nanocrystalline Structure ◽  
Heating Power ◽  
Cast State ◽  
Current Annealing ◽  
Residual Amorphous Matrix ◽  
Crystalline Component

In this study, the evolution of the nanostructure on dc Joule heated Fe72Al5Ga2P11C6B4 metallic glass ribbons have been investigated. Heating power per square area (PS) was ranging between 0.8 to 7.1 W/cm2 in order to get various stages of relaxation or nanocrystallization. The crystallization starts after applying PS ? 4.35 W/cm2 and the sample consist of residual amorphous matrix, a magnetic crystalline component and also a non-magnetic crystalline component (relative abundance of Fe in the crystalline phase is about 35 %). XRD measurements show that crystalline samples after current annealing consist of Fe3B, FeC, FeP and Fe3P compounds. On TEM micrograph a broad distribution of shapes and sizes is noticed, the latter range from about 60 to 350 nm, increasing by applied heating power. The decrease of the electrical resistivity after each current annealing treatment is rather small in comparison with other Fe-based amorphous alloys (only about 1.5 % for the highest PS). Partial nanocrystallization leads to increase of coercive field (from HC ? 7 A/m in the amorphous as-cast state up to 45 A/m) attributed to precipitation of magnetically harder compounds (Fe3B and FeC).

Glass-Forming Ability and Mechanical Properties of Fe-Ni-Zr-Si-B Bulk Glassy Alloys

2005 ◽  
Vol 475-479 ◽  
pp. 3405-3408
Author(s):  
K.A. Lee ◽  
J. Namkung ◽  
Moon Chul Kim
Keyword(s):  
Plastic Strain ◽  
Metallic Glass ◽  
Structural Relaxation ◽  
Amorphous Matrix ◽  
Icosahedral Phase ◽  
Glass Forming Ability ◽  
Glass Forming ◽  
Glassy Alloys ◽  
Partial Crystallization ◽  
Crystallization Onset

The effects of structural relaxation and partial crystallization on the mechanical property of the Ti40Zr29Cu9Ni8Be14 bulk metallic glass (BMG) have been investigated. The atomic structure of the as-cast Ti40Zr29Cu9Ni8Be14 metallic glass transforms into a more relaxed state at the temperature region of 452 –585 K, below the crystallization onset temperature of 631 K. Stable icosahedral phase forms in the amorphous matrix by growth of the pre-existing nuclei in the amorphous matrix during first crystallization step. The compressive plastic strain of the as-cast Ti40Zr29Cu9Ni8Be14 BMG is 6.7 %, and decreases when the structural relaxation occurs. However, the plastic strain increases when a few nanometer size icosahedral phase particles form in the amorphous matrix by the partial crystallization treatment.

Temperature dependence of the soft magnetic character of Fe73.5Cu1Nb3Si13.5B9 amorphous and nanocrystalline alloys

2003 ◽  
Vol 18 (5) ◽  
pp. 1035-1038 ◽  
Author(s):  
J. Gonzáz
Keyword(s):  
Amorphous Alloy ◽  
Current Density ◽  
Curie Point ◽  
Amorphous Matrix ◽  
Body Centered Cubic ◽  
Soft Magnetic ◽  
Current Densities ◽  
Two Phases ◽  
Residual Amorphous Matrix ◽  
Magnetic Hardness

Results on microstructure and coercivity of current-annealed Fe73.5Cu1Nb3Si13.5B9 amorphous alloy treated at different current densities (12–56 A/mm2) and duration (0.5–720 min) are presented. Saturation magnetization and coercivity dependencies with the current density of the nanocrystalline samples is explained by considering the presence of two phases: nanocrystals of Fe(Si) body-centered cubic (bcc) grains and the residual amorphous matrix. An increase in the magnetic hardness observed when the sample was heated by current densities, giving rise to an increase in the sample temperature above the Curie point of the residual amorphous matrix, could be ascribed to exchange and dipolar decoupling of the Fe(Si)-bcc grains.

scholarly journals New Cu-Free Ti-Based Composites with Residual Amorphous Matrix

Materials ◽  
2016 ◽  
Vol 9 (5) ◽  
pp. 331 ◽  
Author(s):  
Mircea Nicoara ◽  
Cosmin Locovei ◽  
Viorel Șerban ◽  
R. Parthiban ◽  
Mariana Calin ◽  
...  
Keyword(s):  
Amorphous Matrix ◽  
Residual Amorphous Matrix

Enhancement of Plasticity in Ti-Based Bulk Metallic Glass

2005 ◽  
Vol 475-479 ◽  
pp. 3409-3414 ◽  
Author(s):  
H.J. Chang ◽  
Won Tae Kim ◽  
Do Hyang Kim
Keyword(s):  
Mechanical Property ◽  
Plastic Strain ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Temperature Region ◽  
Structural Relaxation ◽  
Amorphous Matrix ◽  
Icosahedral Phase ◽  
Partial Crystallization ◽  
Crystallization Onset

The effects of structural relaxation and partial crystallization on the mechanical property of the Ti40Zr29Cu9Ni8Be14 bulk metallic glass (BMG) have been investigated. The atomic structure of the as-cast Ti40Zr29Cu9Ni8Be14 metallic glass transforms into a more relaxed state at the temperature region of 452 –585 K, below the crystallization onset temperature of 631 K. Stable icosahedral phase forms in the amorphous matrix by growth of the pre-existing nuclei in the amorphous matrix during first crystallization step. The compressive plastic strain of the as-cast Ti40Zr29Cu9Ni8Be14 BMG is 6.7 %, and decreases when the structural relaxation occurs. However, the plastic strain increases when a few nanometer size icosahedral phase particles form in the amorphous matrix by the partial crystallization treatment.

scholarly journals Effect of Microstructural Changes during Annealing on Thermoelectromotive Force and Resistivity of Electrodeposited Ni85.8Fe10.6W1.4Cu2.2 Alloy

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
M. Spasojević ◽  
A. Maričić ◽  
Z. Vuković ◽  
S. Đukić ◽  
L. Ribić-Zelenović ◽  
...  
Keyword(s):  
Fermi Level ◽  
Electron Density ◽  
Density Of States ◽  
Structural Relaxation ◽  
Amorphous Matrix ◽  
High Increase ◽  
Temperature Range ◽  
Electron Density Of States ◽  
Phase Crystal ◽  
Fcc Phase

Ni85.8Fe10.6W1.4Cu2.2 alloy powder containing nanocrystals of an FCC-structured solid solution of iron, tungsten, and copper in nickel embedded in an amorphous matrix was electrodeposited from an ammonia citrate solution. The alloy exhibits thermal stability in the temperature range between 25°C and 150°C. Over the range 150−360°C, the alloy undergoes intense structural relaxation which considerably increases the electron density of states and, hence, its electrical conductivity. Less intense structural relaxation takes place at temperatures between 360°C and 420°C. In the temperature range of 420°C to 460°C, relatively more intense changes in the electron density of states at the Fermi level occur, as induced by the structural relaxation resulting from the stabilization of larger less mobile tungsten atoms and copper atoms. The large decrease in electrical resistivity and the high increase in the electron density of states at the Fermi level in the temperature range 460−520°C are due to amorphous matrix crystallization and FCC-phase crystal grain growth.

EFFECT OF ANNEALING AT DIFFERENT TEMPERATURES ON THE STRUCTURE AND HARDNESS OF AL85Y8NI5CO2 ALLOY AMORPHOUS STRIPS

2018 ◽  
pp. 60-67
Author(s):  
A. G. Igrevskaya ◽  
A. I. Bazlov ◽  
N. Yu. Tabachkova ◽  
D. V. Louzguine ◽  
V. S. Zolotorevskiy
Keyword(s):  
Heat Treatment ◽  
Amorphous Alloys ◽  
Amorphous Matrix ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Maximum Value ◽  
Transmission Electron ◽  
Aluminum Solid Solution ◽  
Different Temperatures ◽  
Residual Amorphous Matrix

Aluminum-based metallic glasses are the new promising family of materials. However, the effect of heat treatment on the structure and properties of Al–Y–Ni–Co amorphous alloys has not been widely studied so far. In this paper, Al85Y8Ni5Co2 amorphous alloy strips were obtained by hardening on a rotary copper wheel. The effect of vacuum annealing at temperatures ranging from 100 to 500 °C for 30 minutes on the structure and hardness of these strips was investigated. Transmission electron microscopy, X-ray diffraction analysis, and differential scanning calorimetry were used to study changes in the structure of strips after heat treatment. Vickers microhardness was measured to investigate the effect of annealing on the mechanical properties of strips. The results obtained allowed for the conclusions made about changes in hardness depending on the Al85Y8Ni5Co2 alloy strip structure. It was found that as the temperature rises, strip microhardness increases reaching a maximum value of 575±7 HV after annealing at 350 °C, then it decreases with a further increase in the annealing temperature. It was shown that the Al85Y8Ni5Co2 alloy strips remain completely amorphous and no crystalline phases are detected in their structures after annealing at temperatures up to 250 °C for 30 minutes. A sharp increase in hardness after annealing at 350 °C is associated with 10–30 nm nanocrystals of an aluminum solid solution formed in the amorphous matrix and surrounded by a residual amorphous matrix, while further hardness decrease is associated with the increasing sizes of these crystals and Al3Y and Al19Ni5Y3 intermetallics formed in the structure.

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