Isothermal crystallization kinetics of Fe75Cr5P9B4C7 metallic glass with cost-effectiveness and desirable merits
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In this work, the isothermal crystallization kinetics of cost-effective Fe75Cr5P9B4C7 metallic glass with a combination of desired merits synthesized by industrial ferro-alloys without high-purity materials was evaluated by Johnson–Mehl–Avrami approach using differential scanning calorimeter. The Avrami exponents at all isothermal annealing temperatures range from about 2.93 to 4.61, indicating a three-dimensional diffusion-controlled growth with an increasing nucleation rate during the isothermal crystallization. Meanwhile, the Avrami exponent firstly increases from 2.93 at the initial time to a maximum value of 4.61 and then decreases to 4.09 with the increment of the isothermal annealing temperature, which can be attributed to the atomic diffusion in the alloy. Additionally, the trend of the local Avrami exponent variations at different isothermal annealing temperatures reflects a variable crystallization mechanism during the crystallization process. Moreover, the local activation energy determined by Arrhenius equation gradually decreases from about 412 to 383 kJ mol−1 during the present isothermal crystallization, further revealing that the process is dominated by a three-dimensional diffusion-controlled growth with an increasing nucleation rate, which provides useful insights into the formation of the present alloy.
KeywordsFe-based metallic glass Isothermal Crystallization kinetics Avrami exponent Activation energy
This work was financially supported by National Natural Science Foundation of China (Grant Nos. 51671151, 51371133, 51401156 and 51604223) and the Science and Technology Program of Shaanxi Province (Grant No. 2016KJXX-87).
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