Non-isothermal kinetics of phase transformation for the intermetallic CoSn₃ phase

ABSTRACT

The structure and kinetics of the $\text{β}CoS{n}_3$ phase and its crystallization reaction were studied under nonisothermal conditions using scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). Four isoconversional methods, including Friedman, Kissinger–Akahira–Sunose (KAS), Ozawa–Flynn–Wall (OFW), and Starink, were used to determine the variation in crystallization activation energy$E_{\alpha }\left(T\right)$ with temperature. When the temperature increases by 12 K, the crystallization activation energy of $\text{β}CoS{n}_3$ was reduced by a factor of $\sim 6.5$ in the Friedman method and by a factor of $\sim$4.4 in the remaining methods. The observed behavior of $E_{\alpha }$ as a function of the conversion fraction (α) reveals the multistep mechanism for the formation of the respective phase of $\text{β}CoS{n}_3$. This study also investigated the effect of different heating rates on the reaction model, g(α), in which the chemical reaction rate and the reactant kinetic energy increased by increasing the heating rate.

KEYWORDS:

• Metallic alloy
• CoSn₃ phase
• crystallization reaction
• activation energy
• isoconversion methods

Disclosure statement

No potential conflict of interest was reported by the author(s).