scholarly journals Microstructural Evolution, Thermodynamics and Kinetics of Mo-Tm2O3 Powder Mixtures during Ball Milling

2016 ◽  
Author(s):  
Yong Luo ◽  
Guang Ran ◽  
Nanjun Chen ◽  
Qiang Shen ◽  
Yaoli Zhang
Keyword(s):  
Solid Solution ◽  
Ball Milling ◽  
Microstructural Evolution ◽  
Driving Force ◽  
Phase Evolution ◽  
Heat Of Mixing ◽  
Powder Mixtures ◽  
Thermodynamics And Kinetics ◽  
Transmission Electron ◽  
Kinetics Of

The microstructural evolution, thermodynamics and kinetics of Mo-21%Tm2O3 (mass fraction, %) powder mixtures during ball milling were investigated using X-ray diffraction and transmission electron microscopy. Ball milling induced Tm2O3 to be decomposed and then dissolved into Mo crystal. The supersaturated nanocrystalline solid solution of Mo (Tm, O) was obtained after 96 h of ball milling. The elements of Mo, Tm and O were distributed uniformly in the ball-milled particles. Based on the semi-experimental theory of Miedema, a thermodynamic model was developed to calculate the driving force of phase evolution. There was no chemical driving force to form a crystal solid solution of Tm atoms in Mo crystal or an amorphous phase because the Gibbs free energy for both processes was higher than zero. For Mo-21%Tm2O3, it was mechanical work, not negative heat of mixing, that provided the driving force to form supersaturated nanocrystalline Mo (Tm, O) solid solution.

scholarly journals Microstructural Evolution, Thermodynamics, and Kinetics of Mo-Tm2O3 Powder Mixtures during Ball Milling

Materials ◽  
2016 ◽  
Vol 9 (10) ◽  
pp. 834 ◽  
Author(s):  
Yong Luo ◽  
Guang Ran ◽  
Nanjun Chen ◽  
Qiang Shen ◽  
Yaoli Zhang
Keyword(s):  
Ball Milling ◽  
Microstructural Evolution ◽  
Powder Mixtures ◽  
Thermodynamics And Kinetics ◽  
Kinetics Of

Structural evolution in lead substituted Bi–Sr–Ca–Cu–O superconductors

1991 ◽  
Vol 6 (2) ◽  
pp. 278-288 ◽  
Author(s):  
R. Ramesh ◽  
K. Remschnig ◽  
J.M. Tarascon ◽  
S.M. Green
Keyword(s):  
Structural Evolution ◽  
Homogeneous Sample ◽  
X Ray ◽  
Thermodynamics And Kinetics ◽  
Transmission Electron ◽  
Incommensurate Modulation ◽  
Kinetics Of ◽  
Pb Substitution ◽  
Microstructural Homogeneity

The structural evolution and cationic stoichiometry of Bi(Pb)–Sr–Ca–Cu–O superconductors have been studied using transmission electron microscopy and x-ray microanalysis. The nature of the incommensurate modulation changes systematically as increasing amounts of lead are added. X-ray microanalysis studies reveal that lead replaces Bi in the structure. Pb addition improves the microstructural homogeneity leading to the formation of a nearly homogeneous sample consisting of the “2223” phase. Based upon all the experimental results, it is inferred that the role of Pb substitution is related to the thermodynamics and kinetics of the formation of the n = 3 phase.

Thermodynamics and Kinetics of the Solid Solution of HCl in Ice

1997 ◽  
Vol 101 (18) ◽  
pp. 3554-3565 ◽  
Author(s):  
Emmanuel Thibert ◽  
Florent Dominé
Keyword(s):  
Solid Solution ◽  
Thermodynamics And Kinetics ◽  
Kinetics Of

THERMODYNAMIC ANALYSIS OF PHASE FORMATION IN MECHANICAL ALLOYED Fe3Al POWDER

2011 ◽  
Vol 18 (03n04) ◽  
pp. 115-120
Author(s):  
L. X. PANG ◽  
X. H. HAO ◽  
N. F. HAN ◽  
J. XU ◽  
X. D. TANG ◽  
...  
Keyword(s):  
Solid Solution ◽  
Driving Force ◽  
Lattice Strain ◽  
Driving Forces ◽  
Phase Evolution ◽  
Mechanically Alloyed ◽  
Energy Of Mixing ◽  
Supersaturated Solid Solutions ◽  
Free Energy Of Mixing ◽  
Aluminum Phase

Nanocrystalline supersaturated solid solutions were formed by mechanically alloyed Fe-28Al (in atom percent) from the elemental powder of iron and aluminum. Phase evolution, grain size and lattice strain of these powders were determined and discussed. A thermodynamic model was developed based on semi-experimental theory of Miedema to calculate the chemical driving force for phase evolution. The influence of thermodynamic driving forces, namely the Gibbs free energy of mixing, for the solid solution and the amorphous was discussed and corresponded to the sequence of phase formations during mechanical alloying.

Precipitation of Microalloy Carbo-Nitrides Prior, during and after γ/α Transformation

2005 ◽  
Vol 500-501 ◽  
pp. 75-86 ◽  
Author(s):  
Stanislaw Zajac
Keyword(s):  
Grain Refinement ◽  
Acicular Ferrite ◽  
Driving Force ◽  
Polygonal Ferrite ◽  
Precipitation Strengthening ◽  
Strengthening Mechanisms ◽  
Thermodynamics And Kinetics ◽  
Bainitic Steels ◽  
Kinetics Of

A brief summary is given of the desired effects of precipitation of microalloy nitrides and carbides in austenite and ferrite prior, during and after g−a transformation. Precipitation of microalloy compounds of Nb(C,N), TiC and V(C,N) is discussed in relation to several grain refinement and precipitation strengthening mechanisms. An improved understanding of the thermodynamics and kinetics of precipitation and phase transformations is presented using the approach based on the chemical driving force. Nucleation of intragranular polygonal ferrite on VN particles that grow in austenite and the formation of acicular ferrite inside the austenitic grains in Vsteels is described. The role of carbon in increasing the driving force for nucleation is elucidated and the benefits of using microalloy carbo-nitrides for precipitation strengthening of bainitic steels are reviewed. An expanded view on the role of microalloy carbo-nitrides in grain refinement and precipitation strengthening is presented.

X-ray studies on the kinetics of microstructural evolution of Ni3Al synthesized by ball milling elemental powders

2001 ◽  
Vol 68 (1-3) ◽  
pp. 166-174 ◽  
Author(s):  
S.K Pradhan ◽  
S.K Shee ◽  
A Chanda ◽  
P Bose ◽  
M De
Keyword(s):  
Ball Milling ◽  
Microstructural Evolution ◽  
X Ray ◽  
Kinetics Of

Non-Equilibrium Formation Of Silicon Nitride During Both Ball Milling And Ion Bombardment

1997 ◽  
Vol 481 ◽  
Author(s):  
Z. L. Li ◽  
J. S. Williams ◽  
D. J. Llewellyn ◽  
J. Wong-Leung ◽  
M. Giersig ◽  
...  
Keyword(s):  
Ball Milling ◽  
Analytical Techniques ◽  
Ion Bombardment ◽  
Phase Evolution ◽  
X Ray Diffraction ◽  
Combustion Analysis ◽  
X Ray ◽  
Transmission Electron ◽  
Nitride Formation ◽  
Amorphous Si

ABSTRACTPhase evolution during ball milling of Si in NH3 gas and during subsequent annealing has been studied and compared with nitride formation during ion bombardment of Si. X-ray diffraction, differential thermal analysis, Rutherford backscattering and channeling, combustion analysis and transmission electron microscopy have been used as analytical techniques. Results have shown that an amorphous SixNy(Fe) phase forms during milling which transforms into α-Si3N4 and FeSi2 on annealing. During ion bombardment, slightly N-rich Si3N4 is formed but it is mostly crystalline at temperatures between 150 and 450°C.

Microstructural Evolution in a CeO2-Gd2O3 System

2011 ◽  
Vol 18 (1) ◽  
pp. 162-170 ◽  
Author(s):  
Fei Ye ◽  
Ding Rong Ou ◽  
Toshiyuki Mori
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Microstructural Evolution ◽  
Oxygen Vacancies ◽  
Sudden Change ◽  
Fluorite Structure ◽  
Type Structure ◽  
Defect Clusters ◽  
Structured Matrix ◽  
Transmission Electron

AbstractMicrostructural evolution in a CeO2-Gd2O3 system at atomic and nanoscale levels with increasing Gd concentration has been comprehensively investigated by transmission electron microscopy. When the Gd concentration was increased from 10 to 80 at.%, the phase transformation from ceria with fluorite structure to solid solution with C-type structure was not a sudden change but an evolution in the sequence of clusters, domains, and precipitates with C-type structure in the fluorite-structured matrix. Moreover, the ordering of aggregated Gd cations and oxygen vacancies in these microstructural inhomogeneities developed continuously with increasing Gd concentration. This microstructural evolution can be further described based on the development of defect clusters containing Gd cations and oxygen vacancies.

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