Evolution of structural and dynamic heterogeneities and activation energy distribution of deformation units in metallic glass

2013 ◽  
Vol 102 (10) ◽  
pp. 101903 ◽  
Author(s):  
W. Jiao ◽  
P. Wen ◽  
H. L. Peng ◽  
H. Y. Bai ◽  
B. A. Sun ◽  
...  
Keyword(s):  
Activation Energy ◽  
Metallic Glass ◽  
Energy Distribution

Determination of kerogen activation energy distribution

1992 ◽  
Vol 6 (6) ◽  
pp. 793-803 ◽  
Author(s):  
Padmanabhan Sundararaman ◽  
Paul H. Merz ◽  
Roy G. Mann
Keyword(s):  
Activation Energy ◽  
Energy Distribution

Decreasing activation energy of fast relaxation processes in a metallic glass during aging

2019 ◽  
Vol 99 (14) ◽  
Author(s):  
Martin Luckabauer ◽  
Tomoki Hayashi ◽  
Hidemi Kato ◽  
Tetsu Ichitsubo
Keyword(s):  
Activation Energy ◽  
Metallic Glass ◽  
Relaxation Processes ◽  
Fast Relaxation

Revealing β-relaxation mechanism based on energy distribution of flow units in metallic glass

2016 ◽  
Vol 144 (14) ◽  
pp. 144501 ◽  
Author(s):  
Z. Lu ◽  
B. S. Shang ◽  
Y. T. Sun ◽  
Z. G. Zhu ◽  
P. F. Guan ◽  
...  
Keyword(s):  
Metallic Glass ◽  
Energy Distribution ◽  
Relaxation Mechanism ◽  
Flow Units ◽  
Β Relaxation ◽  
Distribution Of Flow

Stability of the Pd-Co-Ni-Cu-P Metallic Glasses

2007 ◽  
Vol 1048 ◽  
Author(s):  
Daisuke Fukamaki ◽  
Tsunehiro Takeuchi ◽  
Masashi Hasegawa ◽  
Kazuo Soda ◽  
Hirokazu Sato ◽  
...  
Keyword(s):  
Activation Energy ◽  
Thermal Analysis ◽  
Free Energy ◽  
Electronic Structure ◽  
Metallic Glass ◽  
Internal Energy ◽  
Metallic Glasses ◽  
Photoemission Spectroscopy ◽  
First Principle ◽  
Cluster Calculations

AbstractStability of Pd-Co-Ni-Cu-P metallic glass was investigated in terms of free energy using first principle cluster calculations, thermal analysis, and photoemission spectroscopy measurements. We found that the internal energy of the Pd-based metallic glasses is dominated by the electronic structure near the Fermi level. The analyses on the electronic structure and local atomic arrangements indicate that the substitution of cobalt or a hypothetical atom Co0.5Cu0.5 for nickel in the Pd40Ni40P20 metallic glass decreases the free energy of the Pd-Ni-P metallic glass by increasing entropy without altering significantly internal energy. On the basis of the idea mentioned above, we prepared Pd28Co24Ni24P24, Pd25Co25Ni25P25 and Pd40Co40/3Ni40/3Cu40/3P20 metallic glasses. These metallic glasses certainly showed the nearly highest TX, which directly reflect the activation energy against crystallization, among the Pd-based metallic glasses ever reported.

Determination of activation energy for crystallization in metallic glass by small angle X-ray scattering

1992 ◽  
Vol 144 ◽  
pp. 308-311
Author(s):  
Chaofu Meng ◽  
Shong-yan Chen ◽  
Ming-yong Qiao ◽  
Zhen-jie Shao
Keyword(s):  
Activation Energy ◽  
Metallic Glass ◽  
Small Angle ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

scholarly journals Kinetic analysis of the pyrolysis of apricot stone and its main components via distributed activation energy mode

BioResources ◽  
2020 ◽  
Vol 15 (1) ◽  
pp. 1187-1204
Author(s):  
Huanhuan Ma ◽  
Yimeng Zhang ◽  
Liangcai Wang ◽  
Zhengxiang Zhu ◽  
Yu Chen ◽  
...  
Keyword(s):  
Activation Energy ◽  
Energy Distribution ◽  
Apparent Activation Energy ◽  
Early Stage ◽  
Conversion Degree ◽  
Heating Rates ◽  
Continuous Increase ◽  
Thermogravimetric Analyzer ◽  
Energy Mode ◽  
Main Components

The kinetics of pyrolysis of apricot stone and its main components, i.e., lignin, cellulose, and hemicellulose, were investigated via distributed activation energy mode. Experiments were done in a thermogravimetric analyzer at heating rates of 10, 20, 30, and 40 K·min-1 under nitrogen. The activation energy distribution peaks for the apricot stone, lignin, cellulose, and hemicellulose were centered at 246, 318, 364, and 170 kJ·mol-1, respectively. The activation energy distribution for the apricot stone slightly changed; lignin exhibited the widest distribution; and cellulose exhibited the highest activation energy at a conversion degree (α) of less than 0.75. At low pyrolysis temperatures (400 K to 600 K), the pyrolysis of hemicellulose was the main pyrolysis reaction. The apparent activation energy for the apricot stone mainly depended on the pyrolysis of hemicellulose and a small amount of lignin, and the activation energy was low in the early stage of pyrolysis. With the continuous increase in the pyrolysis temperatures (600 K to 660 K), the thermal weight loss of cellulose and lignin was intense. The apparent activation energy for the apricot stone mainly resulted from the pyrolysis of cellulose and lignin, and a higher activation energy was observed in the later stage of pyrolysis.

scholarly journals Devitrification of Zr55Cu30Al15Ni5Bulk Metallic Glass under Heating and HPT Deformation

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1329 ◽  
Author(s):  
Galina Abrosimova ◽  
Boris Gnesin ◽  
Dmitry Gunderov ◽  
Alexandra Drozdenko ◽  
Danila Matveev ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Activation Energy ◽  
Metallic Glass ◽  
Metastable Phase ◽  
Hexagonal Structure ◽  
Crystalline Phases ◽  
Space Group ◽  
Activation Energy Of Crystallization ◽  
Nanocrystal Formation ◽  
Crystallization Stage

The nanocrystal formation in Zr55Cu30Al15Ni5 bulk metallic glass was studied under heat treatment and deformation. The activation energy of crystallization under heating is 278 kJ/mol. Different crystalline phases were found to be formed during crystallization under heating and deformation. At the first crystallization stage, the metastable phase with a hexagonal structure (lattice of space group P63/mmc with the parameters a = 8.66 Å, c = 14.99 Å) is formed under heat treatment. When the temperature rises, the metastable phase decays with the formation of stable crystalline phases. The crystalline Zr2Cu phase with the lattice of space group Fd3m is formed during crystallization under the action of deformation. It was determined that during deformation nanocrystals are formed primarily in the subsurface regions of the samples.

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