Kinetics of fcc-Al nanocrystallization in Al90Tb10 metallic glass

Date

2013-10-15

Author

DEMIRTAS, T.
Kalay, Yunus Eren

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

273
views

0
downloads

The crystallization kinetics of Al90Tb10 amorphous alloy were investigated by a combined study of differential scanning calorimetry (DSC), transmission electron microscopy (TEM), Cu-K alpha X-ray diffraction (XRD) analyses and microhardness measurements. Amorphous to fcc-Al transformation kinetics were descried through Johnson-Mehl-Avrami OMA) approach based on the isothermal DSC hold at 220 degrees C. XRD and TEM revealed the formation of highly populated (similar to 10(21) m(-3)) fcc-Al nanocrystals after the first crystallization event. JMA indicated a three dimensional diffusional growth with constant nucleation rate. TEM and XRD analyses agree well with the three dimensional diffusional growth of fcc-Al within the amorphous matrix. Nucleation of fcc-Al nanocrystals was attributed to already existing Al rich clusters embedded in the amorphous matrix. The deviation in cooling rate at the free and the wheel sides caused variations in Al rich cluster size and population through the thickness of the ribbon specimen. Microhardness tests captured this discrepancy which results in anomalous Avrami exponent, n(x).

Subject Keywords

Materials Chemistry, Electronic, Optical and Magnetic Materials, Condensed Matter Physics, Ceramics and Composites

URI

https://hdl.handle.net/11511/35082

Journal

JOURNAL OF NON-CRYSTALLINE SOLIDS

DOI

https://doi.org/10.1016/j.jnoncrysol.2013.06.020

Collections

Department of Metallurgical and Materials Engineering, Article

Suggestions

OpenMETU
Core

Theoretical prediction of bulk glass forming ability (BGFA) of Ti-Cu based multicomponent alloys SUER, Sila; Mehrabov, Amdulla; Akdeniz, Mahmut Vedat (Elsevier BV, 2009-03-01) The bulk glass forming ability (BGFA) of Ti-Cu based multicomponent alloys has been evaluated via theoretical modeling and computer simulation studies based on a combination of electronic theory of alloys in the pseudopotential approximation and the statistical thermodynamical theory of liquid alloys The. magnitude of atomic ordering energies, calculated by means of the electronic theory of alloys in the pseudopotential approximation, was subsequently used for calculation of the key thermodynamic parameters...
Phase Identification of La-Doped Hard Magnetic Barium Ferrite Using Artificial Neural Network Sozeri, Huseyin; KÜÇÜK, İLKER; Ozkan, Husnu (Springer Science and Business Media LLC, 2011-01-01) A model based on an artificial neural network (ANN) was designed for the simulation and estimation of 2 theta and intensity values obtained by X-Ray Diffraction (XRD) of pure and La-doped barium ferrite powders which have been synthesized in ammonium nitrate melt. Its performance is evaluated by the influences of different La content, sintering temperature, Fe/Ba ratio, and washed in HCl (or not washed in HCl) samples. The XRD patterns of samples estimated by the ANN agree well with the experimental values,...
Optical properties of (Ga2Se3)(0.)(75) - (Ga2S3)(0.)(25) single crystals by spectroscopic ellipsometry Işık, Mehmet; Hasanlı, Nızamı; Gasanova, L. (Elsevier BV, 2019-05-01) Structural and optical properties of 75 mol % Ga2Se3 - 25 mol % Ga2S3 system of single crystals were investigated by experimental techniques of x-ray diffraction (XRD), energy dispersive spectroscopy, Raman spectroscopy and ellipsometry. XRD pattern indicated that the studied compound has crystalline nature with cubic structure. Vibrational modes in the crystal were revealed using Raman spectroscopy experiments in the 90-450 cm(-1) frequency range and nine modes were observed in the spectrum. Ellipsometry m...
Efficient Ceria-Supported Rhodium Nanoparticles as an Electrocatalyst for Hydrogen Evolution Akbayrak, Merve; Önal, Ahmet Muhtar (The Electrochemical Society, 2019-12-13) Rh-0/CeO2 catalystwas prepared by the reduction of Rh+3 ions on CeO2 surface and characterized by transmission electron microscopy, inductively coupled plasma optical emission spectrometry, X-ray photoelectron spectroscopy and powder X-ray diffractometry techniques. To investigate its electrocatalytic activity for H-2 evolution reaction, a glassy carbon electrode (GCE) was modified with Rh-0/CeO2. The modified electrode was found to exhibit a high electrocatalytic activity (turnover frequency (TOF): 1.56 s(...
Initial crystallization in a nanostructured Al-Sm rare earth alloy Kalay, Yunus Eren; Chumbley, L. S.; Kramer, M. J.; Anderson, I. E. (Elsevier BV, 2010-06-15) The transformation kinetics and microstructural evolution during initial crystallization in highly driven Al(90)Sm(10) were investigated using transmission electron microscopy (TEM). conventional Cu K(alpha) and high-energy synchrotron X-ray diffraction (HEXRD) and differential scanning calorimetry (DSC). The highest cooling rate obtained in this study yielded a high number density of fcc-Al nanocrystals, with sizes on the order of 2-5 nm, embedded in a disordered matrix rich in an Al-Sm medium range order ...

Citation Formats

T. DEMIRTAS and Y. E. Kalay, “Kinetics of fcc-Al nanocrystallization in Al90Tb10 metallic glass,” JOURNAL OF NON-CRYSTALLINE SOLIDS, pp. 71–78, 2013, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/35082.