Kinetic methods are routinely employed to determine the kinetic parameters of solid-state transformations from thermal analysis experiments. In particular, there are isoconversional methods which are model-free, i
The second part of this review is devoted to the analysis of complex transformations. In particular, we will describe the use of the isoconversional methods introduced in the first part of this review (Part I [ 1
A nonlinear algorithm has been suggested to increase the accuracy of evaluating the activation energy by the integral isoconversional method. A minor modification of the algorithm has made it possible to adapt the isoconversional method for an arbitrary variation of the temperature. This advanced isoconversional method allows for trustworthy estimates of the activation energy when the thermal effect of a reaction makes the temperature of a sample deviate from a prescribed heating program.
literature. These methods are generally based on either the isokinetic hypothesis or the isoconversional principle and they can be accordingly classified as (1) isokinetic methods where rate of reaction is considered to be the same throughout the temperature
Authors:A. Pratap, T. Lilly Shanker Rao, K. Lad, and Heena Dhurandhar
The crystallization of metallic glasses has been studied quite extensively using differential scanning calorimetry (DSC) technique.
Most methods rely on isokinetic hypothesis for the kinetic analysis of crystallization for which the choice of a reliable
model is very important. Due to inherent uncertainty in the determination of kinetic parameters, the model-free isoconversional
analytical techniques were proposed. However, these isoconversional methods are scarcely used for metallic glasses. In the
present work, the crystallization kinetics of Fe67Co18B14Si1 metallic glass through both isoconversional and isokinetic methods has been investigated and attention has been focused on
the relative applicability of the two methods.
Iso-conversional methods are used for non-isothermal analysis, in which the transformation rate at a constant extent of conversion is only a function of temperature as suggested by Vyazovkin et al. [ 1 – 4 ] and
(activation energy, pre-exponential factor, and conversion function) of each degradation step is one important target of kinetic investigations. Many kinetic analysis methods have been developed, among which isoconversional methods have been widely used [ 1
method, which can not detect the complex nature of the solid-state reaction, has been replaced by multiple scan method at different heating rates using iso-conversional and iso-temperature calculation procedures [ 12 – 14 ]. Among the iso-conversional
Authors:Dinesh Kumar, Inder Pal Singh Kapoor, Gurdip Singh, Nidhi Goel, and Udai Pratap Singh
found to be, respectively, as 63.5 and 38.7 kJ mol −1 .
The isoconversional method [ 34 – 37 ] is known to permit estimation of the apparent activation energy; independent of the model, corresponding to extent of conversion of the sample. This