Table of Contents Author Guidelines Submit a Manuscript
Journal of Nanomaterials
Volume 2016, Article ID 1909108, 9 pages
http://dx.doi.org/10.1155/2016/1909108
Research Article

Crystallization Kinetics of Al-Fe and Al-Fe-Y Amorphous Alloys Produced by Mechanical Milling

1School of Materials Science and Engineering, Hanoi University of Science and Technology, Hanoi, Vietnam
2Lavrentyev Institute of Hydrodynamics SB RAS, Lavrentyev Ave. 15, Novosibirsk 630090, Russia
3Novosibirsk State Technical University, K. Marx Ave. 20, Novosibirsk 630073, Russia
4School of Engineering Physics, Hanoi University of Science and Technology, Hanoi, Vietnam
5School of Materials Science and Engineering, University of Ulsan, San-29, Mugeo-2 Dong, Nam-Gu, Ulsan 680-749, Republic of Korea

Received 11 September 2016; Accepted 24 November 2016

Academic Editor: Edward A. Payzant

Copyright © 2016 Viet H. Nguyen et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

In this work, the effect of a slight change in the composition of the Al-Fe amorphous alloys (from Al84Fe16 to Al82Fe18) and the substitution of Y for Al (2 at.%) on their crystallization kinetics was studied. According to the X-ray diffraction analysis, powders of the Al84Fe16, Al82Fe18, and Al82Fe16Y2 alloys with a fully amorphous structure were formed after 100 h of mechanical milling of the mixtures of the elemental powders. The crystallization behavior of the alloys was also studied by transmission electron microscopy. Upon heating up to a temperature of the first exothermic peak, α-Al crystals precipitated from the amorphous Al84Fe16 matrix. During crystallization of the Al82Fe18 alloy, crystals of the Al6Fe intermetallic compound formed along with α-Al crystals. Substitution of Y for 2 at.% of Al in the Al82Fe16Y2 alloy made crystallization of the alloy more complicated: α-Al, Al6Fe, and Fe4Y crystals coexisted with an amorphous phase. The activation energies corresponding to the first crystallization event of the alloys were calculated using the Kissinger and Ozawa methods. The values obtained by these two methods were in good agreement with each other and the same trends of changing with the alloy composition were observed. The Avrami exponent was determined from the Johnson-Mehl-Avrami equation and showed that crystallization at the first stage is interface-controlled growth for all the three powder alloys studied.