Study of the crystallization kinetics of a Zr57Cu15.4Ni12.6Al10Nb5 amorphous alloy

Abstract The non-isothermal crystallization kinetics with heating rates ranging from 10 K s-1to 80 K s-1and the isothermal crystallization kinetics during annealing from the glass transition temperature to the crystallization onset temperature of a Zr57Cu15.4Ni12.6Al10Nb5 amorphous alloy were studied in detail using X-ray diffraction and differential scanning calorimetry. During non-isothermal crystallization, it is more difficult to nucleate than to grow, and the crystallization resistance increases first and then decreases. During isothermal crystallization of the alloy from 713- 728 K, there are two exothermic peaks corresponding to a diffusion-controlled growth process with decreasing nucleation rate and increasing nucleation rate. From 733- 748 K, only one exothermic peak appears, and the growth process is controlled by the interface with decreasing nucleation rate. Isothermal crystallization is a process in which the crystallization resistance increases. The resistance of isothermal crystallization is less than that of non-isothermal crystallization.

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Non-Isothermal Crystallization Kinetics of Co67Fe4Cr7Si8B14 Amorphous Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.706-709.1311 ◽

2012 ◽

Vol 706-709 ◽

pp. 1311-1317 ◽

Cited By ~ 4

Author(s):

S.A. Hasheminezhad ◽

M. Haddad-Sabzevar ◽

S. Sahebian

Keyword(s):

Activation Energy ◽

Amorphous Alloy ◽

Crystallization Kinetics ◽

Isothermal Crystallization ◽

Frequency Factor ◽

Heating Rates ◽

Scanning Calorimetry ◽

Kinetics Parameters ◽

Isothermal Crystallization Kinetics ◽

Kinetics Of

Non-isothermal crystallization kinetics of Co67Fe4Cr7Si8B14amorphous ribbons was studied by differential scanning calorimetry (DSC) technique under 10, 20, 30, 40 and 80 °Cmin-1heating rates. It is found that Co67Fe4Cr7Si8B14amorphous alloy exhibits two-stage crystallization on heating. The two crystallization peaks shift to higher temperatures with increasing heating rate. The apparent activation energies (EC) for the first stage of crystallization were determined as 443.44 and 434.47 kJmol-1by using the Kissinger and Ozawa equations, respectively. Frequency factor (A) estimated to be 1.084×1026s-1using Kissinger equation. Kinetics parameters such as Crystallization exponent (n) and dimensionality of growth (Ndim) were determined using JMA (Johnson-Mehl-Avrami) method. Details of the nucleation and growth behaviours during the non-isothermal crystallization were studied in terms of local activation energy EC(x) by the OFW (Ozawa, Flynn and Wall) method. Also the activation energy for nucleation (En) and growth (Eg) separately estimated.

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Thermal Properties and Non-Isothermal Crystallization Kinetics of Poly (δ-Valerolactone) and Poly (δ-Valerolactone)/Titanium Dioxide Nanocomposites

Crystals ◽

10.3390/cryst8120452 ◽

2018 ◽

Vol 8 (12) ◽

pp. 452 ◽

Cited By ~ 3

Author(s):

Waseem Saeed ◽

Abdel-Basit Al-Odayni ◽

Abdulaziz Alghamdi ◽

Ali Alrahlah ◽

Taieb Aouak

Keyword(s):

Titanium Dioxide ◽

Crystallization Kinetics ◽

Isothermal Crystallization ◽

Three Dimensional ◽

Degree Of Crystallinity ◽

Simultaneous Occurrence ◽

Scanning Calorimetry ◽

Isothermal Crystallization Kinetics ◽

The Stability ◽

Kinetics Of

New poly (δ-valerolactone)/titanium dioxide (PDVL/TiO2) nanocomposites with different TiO2 nanoparticle loadings were prepared by the solvent-casting method and characterized by Fourier transform infra-red, differential scanning calorimetry, X-ray diffraction and scanning electron microscopy, and thermogravimetry analyses. The results obtained reveal good dispersion of TiO2 nanoparticles in the polymer matrix and non-formation of new crystalline structures indicating the stability of the crystallinity of TiO2 in the composite. A significant increase in the degree of crystallinity was observed with increasing TiO2 content. The non-isothermal crystallization kinetics of the PDVL/TiO2 system indicate that the crystallization process involves the simultaneous occurrence of two- and three-dimensional spherulitic growths. The thermal degradation analysis of this nanocomposite reveals a significant improvement in the thermal stability with increasing TiO2 loading.

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Non-isothermal crystallization kinetics and fragility of (Cu46Zr47Al7)97Ti3 bulk metallic glass investigated by differential scanning calorimetry

Thermochimica Acta ◽

10.1016/j.tca.2013.04.017 ◽

2013 ◽

Vol 565 ◽

pp. 132-136 ◽

Cited By ~ 24

Author(s):

Man Zhu ◽

Junjie Li ◽

Lijuan Yao ◽

Zengyun Jian ◽

Fang’e Chang ◽

...

Keyword(s):

Differential Scanning Calorimetry ◽

Metallic Glass ◽

Bulk Metallic Glass ◽

Crystallization Kinetics ◽

Isothermal Crystallization ◽

Scanning Calorimetry ◽

Isothermal Crystallization Kinetics

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Non-Isothermal Crystallization Kinetics of Mg61Zn35Ca4 Glassy Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.898.657 ◽

2017 ◽

Vol 898 ◽

pp. 657-665

Author(s):

Dao Zhang ◽

Wang Shu Lu ◽

Xiao Yan Wang ◽

Sen Yang

Keyword(s):

Activation Energy ◽

Crystallization Kinetics ◽

Isothermal Crystallization ◽

Melt Spinning ◽

Glassy Alloy ◽

Heating Rates ◽

Isothermal Crystallization Kinetics ◽

Complex Process ◽

Activation Energy Of Crystallization ◽

Kinetics Of

The non-isothermal crystallization kinetics of Mg61Zn35Ca4 glassy alloy prepared via melt-spinning were studied by using isoconversion method. The crystalline characterization of Mg61Zn35Ca4 was examined by X-ray diffraction. Different scanning calorimeter was used to investigate the non-isothermal crystallization kinetics at different heating rates (3-60 K/min). The calculated value of Avrami exponent obtained by Matusita method indicated that the crystalline transformation for Mg61Zn35Ca4 is a complex process of nucleation and growth. The Kissinger-Akahira-Sunose method was used to investigate the activation energy. The activation energy of crystallization varies with the extent of crystallization and hence with temperature. The Sestak-Berggren model was used to describe the non-isothermal crystallization kinetics.

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Non-Isothermal Crystallization Behavior of Poly(trimethylene Terephthalate-Co-Isophthalate) Copolyesters

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.535-537.1413 ◽

2012 ◽

Vol 535-537 ◽

pp. 1413-1416

Author(s):

Tien Wei Shyr ◽

Chia Hsin Tung ◽

Yan Ting Liu

Keyword(s):

Isothermal Crystallization ◽

Reaction Rate ◽

Glassy State ◽

Exothermic Peak ◽

Avrami Equation ◽

Scanning Calorimetry ◽

Isothermal Crystallization Kinetics ◽

1H Nuclear Magnetic Resonance ◽

Thermal Nucleation ◽

Trimethylene Terephthalate

Poly(trimethylene terephthalate-co-isophthalate) (TI) copolyesters were synthesized using different ratios of isophthalic acid (IPA) and Terephthalic acid (TPA) with 1,3-propanediol (1,3-PDO). The compositions of TI copolyesters were analyzed using 1H nuclear magnetic resonance (NMR). Non-isothermal melt- and cold-crystallization and subsequent melting behaviors were investigated using differential scanning calorimetry (DSC). For TI0, TI10, and TI20, non-isothermal crystallization kinetics were analyzed using a modified Avrami equation. The results show that the reaction rate of TPA with 1,3-PDO was similar with that of IPA with 1,3-PDO in TI copolyesters. Crystallization exothermic peak and melting endothermic peak were not observed in DSC traces with an increase of the relative amount of PIP to 41%. The Avrami exponent n is in the range of 3.5-4.2 for melt-crystallized TI copolyesters and between 3.0-3.2 for cold-crystallized copolyesters. It suggests that the crystallization from melt state corresponds to thermal nucleation but the crystallization from glassy state originates from predeterminated nuclei.

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