Nanostructured surfaces

Kinetic parameters of nanostructures of the Al-based amorphous alloys
Khrushchyk Kh.I.1, Hula T.H.1, Boichyshyn L.M.1
1Faculty of Chemistry, Ivan Franko National University of Lviv, Kyryla and Mefodiya str., 6, 79005 Lviv, Ukraine
E-mail: hrystynahrushchykchemist@ukr.net

Amorphous metallic alloys (AMA) are the new kind of material in which there is no crystalline structure, it does not contain cells, defects between crystals, etc [1].
The aim of research was to investigate kinetic parameters and determine activation energy (Ea) (Table 1) of transformation (used Kissinger, Ozawa, Augis- Bennet models) mechanisms of nanocrystallization on the ﬁrst step of the AMA crystallization.
The Al-RE-Ni amorphous ribbons of 30 m thickness were produced by melt spinning technique (G.V. Kurdyumov Institute For Metal Physics, NAS of Ukraine, Kyiv) with the following composition: Al87Ni8Y5, Al87Ni8Gd5, Al87Ni8Dy5 and Al87Ni8Y4Dy1.
Investigation methods were differential scanning calorimetry (DSC) and scanning electron microscopy (SEM).
Table 1. The activation energy of transformations mechanisms of AMA nanocrystallization 
AMA	Ea (Kissinger), kJ/mol	Ea (Оzawa), kJ/mol	Ea (Augisa-Bennet),
kJ/mol	
Al87Ni8Y5	198	207	202	
Al87Ni8Gd5	177	185	181	
Al87Ni8Y4Dy1	251	259	263	
Al87Ni8Dy5	196	203	199	
The measured activation energy of AMA was in range from 177 to 251 kJ/mol. Doping Al87Ni8Dy5 alloy with 4 at. % of Y increases Ea from 196 to 251 kJ/mol.
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