Nonisothermal Kinetics Study of Phase Evolution of Zn-Fe Intermetallics

1995 ◽  
Vol 398 ◽  
Author(s):  
O. N. C. Uwakweh ◽  
Z. T. Liu ◽  
M. Boisson
Keyword(s):  
Mechanical Alloying ◽  
Phase Evolution ◽  
Activation Energies ◽  
Intermetallic Phases ◽  
Kinetics Study ◽  
Nonisothermal Kinetics ◽  
Thermally Induced ◽  
Fe Intermetallics

ABSTRACTThrough mechanical alloying of pure elemental powders of Fe and Zn, true homogeneous alloys of Γ (Fe3Zn10), Γ1 (Fe5Zn21), δ (FeZn7) and ζ (FeZn13) intermetallic phases are formed. Based on nonisothermal kinetics analyses, the highest activation energies associated with the metastable to stable transformations of these phases are determined as follows: 170±1 kJ/mol, 2 51±2 kJ/mol, 176±1 kJ/mol and 73 7±4 kJ/mol for the Γ, Γ1, δ and ζ-phases, respectively. These values reflect different diffusion/thermally induced processes associated with the transition of each of these phases.

Formation of intermetallic phases during mechanical alloying and annealing of Cr + 20 wt % al mixtures

2008 ◽  
Vol 44 (6) ◽  
pp. 587-591 ◽  
Author(s):  
J. S. Kim ◽  
Y. S. Kwon ◽  
G. V. Golubkova ◽  
O. I. Lomovsky ◽  
D. V. Dudina ◽  
...  
Keyword(s):  
Mechanical Alloying ◽  
Intermetallic Phases

The influence of Fe3+ doping on thermally induced crystallization and phase evolution of amorphous calcium phosphate

CrystEngComm ◽  
2021 ◽  
Author(s):  
Diana Griesiute ◽  
Lauryna Sinusaite ◽  
Agne Kizalaite ◽  
Andris Antuzevics ◽  
Kestutis Mazeika ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Amorphous Calcium Phosphate ◽  
Phase Evolution ◽  
Thermally Induced ◽  
Induced Crystallization

The present study investigates thermally induced crystallization and phase evolution of amorphous calcium phosphate (ACP) partially substituted with Fe3+ ions (M/P = 1.5 : 1). It was demonstrated that the...

Phase evolution of Mg–Al–Zr nanophase alloys prepared by mechanical alloying

2005 ◽  
Vol 400 (1-2) ◽  
pp. 96-99 ◽  
Author(s):  
N. Al-Aqeeli ◽  
G. Mendoza-Suarez ◽  
A. Labrie ◽  
R.A.L. Drew
Keyword(s):  
Mechanical Alloying ◽  
Phase Evolution

scholarly journals Water Uptake in PHBV/Wollastonite Scaffolds: A Kinetics Study

2019 ◽  
Vol 3 (3) ◽  
pp. 74 ◽  
Author(s):  
Ribas ◽  
Montanheiro ◽  
Montagna ◽  
Prado ◽  
Campos ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Phase Separation ◽  
Cell Growth ◽  
Cell Viability ◽  
Water Uptake ◽  
Kinetic Mechanism ◽  
Kinetics Study ◽  
Biological Applications ◽  
Thermally Induced Phase Separation ◽  
Thermally Induced

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a widely studied polymer and it has been found that porous PHBV materials are suitable for substrates for cell cultures. A crucial factor for scaffolds designed for tissue engineering is the water uptake. This property influences the transport of water and nutrients into the scaffold, which promotes cell growth. PHBV has significant hydrophobicity, which can harm the production of cells. Thus, the addition of α-wollastonite (WOL) can modify the PHBV scaffold’s water uptake. To our knowledge, a kinetics study of water uptake of α-wollastonite phase powder and the PHBV matrix has not been reported. In this work, PHBV and WOL, (PHBV/WOL) films were produced with 0, 5, 10, and 20 wt % of WOL. Films were characterized, and the best concentrations were chosen to produce PHBV/WOL scaffolds. The addition of WOL in concentrations up to 10 wt % increased the cell viability of the films. MTT analysis showed that PHBV/5%WOL and PHBV/10%WOL obtained cell viability of 80% and 98%, respectively. Therefore, scaffolds with 0, 5 and 10 wt % of WOL were fabricated by thermally induced phase separation (TIPS). Scaffolds were characterized with respect to morphology and water uptake in assay for 65 days. The scaffold with 10 wt % of WOL absorbed 44.1% more water than neat PHBV scaffold, and also presented a different kinetic mechanism when compared to other samples. Accordingly, PHBV/WOL scaffolds were shown to be potential candidates for biological applications.

Thermally induced nucleation. I. A new way to obtain activation energies for unimolecular reactions

1983 ◽  
Vol 79 (6) ◽  
pp. 2763-2770 ◽  
Author(s):  
Joseph L. Katz ◽  
Joseph G. Ruggiero ◽  
Richard Partch ◽  
Dale Warren ◽  
F. H. Ebetino
Keyword(s):  
Activation Energies ◽  
Unimolecular Reactions ◽  
Thermally Induced

Thermally induced crystallization and phase evolution in powders derived from amorphous calcium phosphate precipitates with a Ca/P ratio of 1:1

2016 ◽  
Vol 450 ◽  
pp. 190-196 ◽  
Author(s):  
Zoltan Zyman ◽  
Matthias Epple ◽  
Anton Goncharenko ◽  
Dmytro Rokhmistrov ◽  
Oleg Prymak ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Amorphous Calcium Phosphate ◽  
Phase Evolution ◽  
Thermally Induced ◽  
Induced Crystallization

Phase evolution in Al–Ni–(Ti, Nb, Zr) powder blends by mechanical alloying

2007 ◽  
Vol 464 (1-2) ◽  
pp. 306-314 ◽  
Author(s):  
A. Samanta ◽  
I. Manna ◽  
P.P. Chattopadhyay
Keyword(s):  
Mechanical Alloying ◽  
Phase Evolution ◽  
Powder Blends

Phase Evolution in Fe-Cr-Mn-Mo Powders Processed By Mechanical Alloying in N2 Atmosphere

2001 ◽  
Vol 10 ◽  
pp. 189-194
Author(s):  
H. Mancha ◽  
G. Mendoza-Suárez ◽  
S. Belmares ◽  
M.M. Cisneros ◽  
J.I. Escalante ◽  
...  
Keyword(s):  
Mechanical Alloying ◽  
Phase Evolution

Effect of WC content on glass formation, thermal stability, and phase evolution of a TiNbCuNiAl alloy synthesized by mechanical alloying

2008 ◽  
Vol 23 (3) ◽  
pp. 745-754 ◽  
Author(s):  
Y.Y. Li ◽  
C. Yang ◽  
W.P. Chen ◽  
X.Q. Li
Keyword(s):  
Thermal Stability ◽  
Mechanical Alloying ◽  
Volume Fraction ◽  
High Volume ◽  
Supercooled Liquid ◽  
Phase Evolution ◽  
Supercooled Liquid Region ◽  
Glassy Matrix ◽  
Liquid Region ◽  
The Matrix

Amorphous Ti66Nb13Cu8Ni6.8Al6.2 alloy powders with different tungsten carbide (WC) contents were synthesized by mechanical alloying. Outstanding differences in particle size, thermal stability, glass-forming ability, and phase evolution are found for the synthesized Ti-based glassy powders with different WC contents. This is attributed to the fact that the WC was partially alloyed into the glassy matrix and the matrix element Ti was also partially alloyed into the WC particles. The obtained glassy powders exhibit a wide supercooled liquid region above 64 K. Meanwhile, the main crystalline phase is the ductile β-Ti with a high volume fraction in the crystallized alloy powders. These two aspects offer the possibility of easily preparing a plasticity-enhanced bulk composite in the supercooled liquid region by powder metallurgy, which couples the nanosized WC particles with in situ precipitated ductile β-Ti phase.

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