Non-isothermal Crystallization Kinetics of Co67Fe4Cr7Si8B14 Amorphous Alloy

Non-isothermal crystallization kinetics of Co67Fe4Cr7Si8B14 amorphous ribbons was studied by differential scanning calorimetry (DSC) technique under 10, 20, 30, 40 and 80 degrees Cmin(-1) heating rates. It is found that Co67Fe4Cr7Si8B14 amorphous alloy exhibits two-stage crystallization on heating. The two crystallization peaks shift to higher temperatures with increasing heating rate. The apparent activation energies (E-C) for the first stage of crystallization were determined as 443.44 and 434.47 kJmol(-1) by using the Kissinger and Ozawa equations, respectively. Frequency factor (A) estimated to be 1.084x10(26) s(-1) using Kissinger equation. Kinetics parameters such as Crystallization exponent (n) and dimensionality of growth (N-dim) were determined using JMA (Johnson-Mehl-Avrami) method. Details of the nucleation and growth behaviours during the non-isothermal crystallization were studied in terms of local activation energy E-C(x) by the OFW (Ozawa, Flynn and Wall) method. Also the activation energy for nucleation (E-n) and growth (E-g) separately estimated.