Non-isothermal nanocrystallization of Fe83.3Si4B8P4Cu0.7 (NANOMET®) alloy: modeling and the heating rate effect on magnetic properties
Non-isothermal nanocrystallization of Fe83.3Si4B8P4Cu0.7 (NANOMET®) alloy: modeling and the heating rate effect on magnetic properties
复制标题
DOI：
10.1088/1361-6463/ab795d
复制
发表时间：
2020-03
期刊：
影响因子：
--
通讯作者：
E. Dastanpour;M. Enayati;V. Ström
中科院分区：
文献类型：
--
作者：
E. Dastanpour;M. Enayati;V. Ström
采用差示扫描量热法研究了Fe83.3Si4B8P4Cu0.7非晶合金在10 °C min-1至200 °C min-1的宽加热速率范围内的非等温退火动力学。采用快淬法制备了非晶合金，其晶化过程为两阶段晶化。在第一晶化阶段，形成α-Fe纳米晶。该相负责良好的软磁性能。用等转化率法测定了α-Fe纳米晶相晶化过程的激活能，发现其在晶化过程中有明显的变化。试图在活化能相对恒定的区间内模拟结晶过程。Malek准则表明Kolmogorov-Johnson-Mehl-Avrami模型是不合适的，而Sestak-Berggren模型满足该准则。所得模型与实验结果吻合较好。不同加热速率下退火薄带的磁性显示，初始磁化强度（Hc）急剧下降，从加热速率为10 ° C min − 1时的82 A m−1下降到100 °C min−1以上的20 A m− 1，而饱和磁化强度（Ms）在约175 Am 2 kg−1时几乎不变。这种依赖性被解释为由于减小晶粒尺寸与较高的加热速率，这是进一步支持的X射线衍射测量。
The kinetics of the nanocrystallization of a Fe83.3Si4B8P4Cu0.7 amorphous alloy by using differential scanning calorimetry has been investigated by non-isothermal annealing in a wide heating rate range from 10 °C min−1 to 200 °C min−1. The amorphous alloy was prepared by melt-spinning and showed a two-stage crystallization. In the first crystallization stage, α-Fe nanocrystals are formed. This phase is responsible for the good soft magnetic properties. The activation energy during the crystallization of the α-Fe nanocrystalline phase was determined from an isoconversional approach, and was found to be distinctively varying during the crystallization. An attempt was made to model the crystallization in an interval where the activation energy is relatively constant. The Malek criterion indicated that the Kolmogorov–Johnson–Mehl–Avrami model is not appropriate, whereas the Sestak–Berggren model meets the criterion. The acquired model shows good agreement with the experimental results. The magnetic properties of annealed ribbons at different heating rates show an initially steep decrease of the coercivity (Hc) from 82 A m−1 at a heating rate of 10 °C min−1 to 20 A m−1 above 100 °C min−1, whereas saturation magnetization (Ms) is practically invariant at ca 175 Am2 kg−1. This dependence is explained as due to diminishing grain size with higher heating rates, which is further supported by x-ray diffraction measurements.