Ozawa-Avrami model is a kinetic model to calculate the Avrami exponent (n). As I studied in the literature, it is usually used in the polymers. Is it possible to use it for Metallic Glasses? and If yes, according to the model:
ln(B)=bln(t)+cte.
and b=n/m
How to extract the mechanism from b?
Thanks.
Dear Saman Mostafapoor,
The Avriami-type of kinetic equations are usually applied to study thermally activated transformations. So, in case the transformation in your metallic glasses can be conceived as thermally activated I would try.
Dear P. Van Mourik
Thanks for your answer
I've used avrami model.
But I asked about combined avrami-ozawa model.
Strictly speaking KJMA or Avarami equation is (deduced) to be used for describing isothermal solid state transformations. However, it has also been widely applied for cases of non-isothermal solid state transformations. As far as I know, the Ozawa model treats non-isothermal process as an infinite number of small isothermal steps and assumes a constant heating/cooling rate. I like to add that I have worked on the analysis creep in the framework of first order reaction rate kinetics and I have interacted with my colleagues (working on corrosion in stainless steel welds) on the application KJMA analysis (pseudo - first order kinetics) for studying delta ferrite transformation in stainless steels.
With my limited knowledge on metallic glasses, I suppose that you can apply the Ozawa equation for metallic glasses. I have come across a few references where Avarami (KJMA), Ozawa, Kissinger equations have been applied for metallic glasses.
Please see the following references and may be useful:- (1) "Crystallization Kinetics of Metallic Glasses", Arun Pratap and Ashmi T. Patel, Advances in Crystallization Processes - www.intechopen.com (link: http://cdn.intechopen.com/pdfs-wm/36354.pdf). (2) "Bulk Metallic Glasses", By C. Suryanarayana, A. Inoue, Chapter 5, CRC Press, 2011. (3) "Non-Isothermal Kinetic Analysis of the Crystallization of Metallic Glasses Using the Master Curve Method", Joan Torrens-Serra ET AL., Materials 2011, 4, 2231-2243; doi:10.3390/ma4122231. (4) "Crystallization kinetics of Fe78Si9B13 metallic glass", E. JAKUBCZYK ET AL., Optica Applicata, Vol. XXXVII, No. 4, 2007. (5) "Assessment of Avrami, Ozawa and Avrami–Ozawa equations
for determination of EVA crosslinking kinetics from DSC measurements", O. Bianchi ET AL., Polymer Testing 27 (2008) 722–729.
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