On the activation energy of crystallization in metallic glasses

Gao, Yifan; Wang, Wego

doi:10.1016/0022-3093(86)90262-0

Cited by 187 publications

(84 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A method suggested by Gao and Wang (Gao & Wang, 1986) is a special case of the Friedman method. This method uses the following expression to determine the activation energy.…”

Section: Linear Differential Isoconversional Methodsmentioning

confidence: 99%

“…The linear integral isoconversional methods (Kissinger, 1957;Ozawa, 1965;Augis & Bennett, 1978;Boswell, 1980;Flynn & Wall, 1966;Akahira & Sunose, 1971;Li & Tang, 1999) depend on the approximation of the temperature integral and require the data on T α (β). The differential isoconversional methods depend on the rate of transformation at T α (β) and the data on T α (β) (Gupta et al, 1988;Friedman, 1964;Gao & Wang, 1986). Vyazovkin (Vyazovkin & Wight, 1997) introduced a non-linear isoconversional method to increase the accuracy of evaluating the activation energy.…”

Section: Isoconversional Analysismentioning

confidence: 99%

See 1 more Smart Citation

Crystallization Kinetics of Metallic Glasses

Pratap¹,

Patel²

2012

Advances in Crystallization Processes

View full text Add to dashboard Cite

“…A method suggested by Gao and Wang (Gao & Wang, 1986) is a special case of the Friedman method. This method uses the following expression to determine the activation energy.…”

Section: Linear Differential Isoconversional Methodsmentioning

confidence: 99%

Section: Isoconversional Analysismentioning

confidence: 99%

Crystallization Kinetics of Metallic Glasses

Pratap¹,

Patel²

2012

Advances in Crystallization Processes

View full text Add to dashboard Cite

“…Kissinger [17], Augis-Bennett [18] and Gao-Wang [19] methods. A set of four scans obtained at heating rates of 5, 10, 20 and 40 K/min was used for each alloy.…”

Section: Calorimetrymentioning

confidence: 99%

Partial substitution of Co and Ge for Fe and B in Fe–Zr–B–Cu alloys: microstructure and soft magnetic applicability at high temperature

et al. 2005

View full text Add to dashboard Cite

The partial substitutions of Co for Fe and Ge for B are studied for a Fe 83-x Co x Zr 6 B 10-y Ge y Cu 1 alloy series (x = 0, 5 and 20; y = 0 and 5) as a possible way to enhance the high temperature applicability of NANOPERM alloys. The devitrification process, the nanocrystallization kinetics and the nanocrystalline microstructure are similar for all the studied alloys. Good soft magnetic properties are observed even at a high crystalline volume fraction of bcc -Fe nanocrystals, which are stable up to ~1000 K. The partial substitution of Co for Fe is very effective to increase the Curie temperature of the residual amorphous matrix (T C AM ). Although the substitution of Ge for B is ineffective to increase T C AM , a clear increase of the saturation magnetization with respect to the Ge-free alloy can be observed. These nanocrystalline compositions have a high concentration of Fe and a typical composition: Fe-M-ET-(Cu), where M is a metalloid and ET is an early transition metal. The addition of metalloids, such as B, P, Si, etc., is necessary to enable the production of a precursor amorphous alloy by rapid quenching techniques, from which the nanocrystalline microstructure is obtained after controlled crystallization. It is important to distinguish two different kinds of metalloids: those highly soluble in the -Fe phase (e.g. Si) and those whose solubility in this phase is very restricted (e.g. B). The former elements will be generally dissolved in the crystalline phase, increasing the crystalline volume fraction but deteriorating some magnetic properties like the saturation magnetization and the Curie temperature of the crystalline phase. The latter elements will remain in the amorphous matrix and will diminish the maximum volume fraction of nanocrystals, although preserving the purity of the -Fe phase.The early transition metals (Zr, Nb, Hf, etc.) have a very low solubility in the -Fe phase and, consequently, will remain in the amorphous matrix. However, due to the very slow diffusivity of these elements in the amorphous phase, they pile up at the crystal-matrix interface and constrain the growth of the crystalline phase to the nanocrystalline scale. was proposed mainly because of the strong increase of the Curie temperature of the residual amorphous phase (T C AM ) due to the partial substitution of Co for Fe with respect to the Cofree NANOPERM alloy [7]. In fact, the exchange coupling between nanocrystals is transmitted through the ferromagnetic residual amorphous matrix and thus, at temperatures above the Curie temperature of this residual amorphous matrix, the nanocrystals become exchange uncoupled and, consequently, the outstanding soft magnetic properties of these In this work, the combined effect of partial substitution of Co for Fe and Ge for B on the microstructure and the magnetic properties of nanocrystalline alloys is studied. The maximum Co concentration studied in the alloys is 20 at. %, in order to search for a new showed that this parameter is seriously deteriorated for higher Co con...

show abstract

“…Such cases are referred as non-isothermal conditions. Temperature of a sample and heating rate are linearly dependent on each other as [22,23]:…”

Section: Theoretical Backgroundmentioning

confidence: 99%

Experimental and theoretical approaches on thermal and structural properties of Zn doped BSCCO glass ceramics

Koralay

Hicyilmaz

Çavdar

et al. 2016

Materials Science-Poland

View full text Add to dashboard Cite

Thermal properties of Cu-Zn partially substituted Bi 1.8 Sr 2 Ca 2 Cu 3.2−x Zn x O 10+δ (x = 0, 0.1 and 0.5) glass-ceramic systems have been investigated with the help of a differential thermal analyzer (DTA) by using Johnson-Mehl-Avrami-Kolmogorov (JMAK) approximation. Non-isothermal crystallization kinetics of the samples has been tested. The calculated values of activation energy of crystallization (E) and Avrami parameter (n) ranged between 306.1 and 338.3 kJ·mol −1 and 1.29 and 3.59, respectively. Crystallization kinetics was compared following the partial substitution, before and after Zn doping of the sample. In addition, by using a scanning electron microscope (SEM) and X-ray powder diffractometer (XRD), structural properties of Zn doped BSCCO glass-ceramic samples were determined. Surface morphology of the samples was studied by SEM measurements. Lattice parameters and volume of the samples were calculated from the XRD measurements.

show abstract

On the activation energy of crystallization in metallic glasses

Cited by 187 publications

References 5 publications

Crystallization Kinetics of Metallic Glasses

Crystallization Kinetics of Metallic Glasses

Partial substitution of Co and Ge for Fe and B in Fe–Zr–B–Cu alloys: microstructure and soft magnetic applicability at high temperature

Experimental and theoretical approaches on thermal and structural properties of Zn doped BSCCO glass ceramics

Contact Info

Product

Resources

About