Influence of the preparation cooling rate on crystallization kinetics of Fe74Mo6P13C7 amorphous alloys

Abstract Fe 74 Mo 6 P 13 C 7 amorphous alloys have been prepared by three techniques with different preparation cooling rates, namely the melt-spinning, copper-mold casting, and J-quenching techniques. Differential scanning calorimetry (DSC) was used to investigate the thermal behavior and non-isothermal crystallization kinetics of the amorphous alloy samples. Through this, the effect of the preparation cooling rate on the amorphous alloy thermal parameters, apparent activation energy ( E app ), and first crystallization event kinetics were investigated. The DSC tests show that there are no significant differences in the glass transition temperature ( T g ) and the initial crystallization temperature ( T x ) among the Fe 74 Mo 6 P 13 C 7 amorphous alloy samples prepared by the different techniques, but the total crystallization heat increases with the preparation cooling rate. The E app values corresponding to the first crystallization events of the three amorphous alloy samples are determined by the Kissinger and Ozawa methods, and the results show that E app increases with a decreasing preparation cooling rate. This indicates that the amorphous alloy sample prepared at the lower cooling rate has a larger crystallization resistance, which may be ascribed to the lesser free volume. The non-isothermal kinetics analyses of the first crystallization events show that the local Avrami exponents ( n ) of the three amorphous alloy samples are n n  > 2.5) nucleation rates. Meanwhile, the n values increase with the preparation cooling rate, indicating more short-range order in the amorphous alloy sample prepared at the lowest cooling rate.