Improvement of soft magnetic properties of Fe0.7Nb0.1Zr0.1Ti0.1 amorphous alloy: A kinetic study approach

In this paper, the crystallization kinetic of amorphous Fe0.7Nb0.1Zr0.1Ti0.1 was studied by differential thermal analysis to produce an appropriate amorphous/nanocrystalline microstructure for improving the soft magnetic properties. Amorphous Fe0.7Nb0.1Zr0.1Ti0.1 alloy without metalloids was prepared by mechanical alloying of pure elements. The results showed that Johnson-Mehl-Avrami model was able to explain the crystallization kinetic of products as: dαdt=βdαdT=4.86×109exp−186776RT1−α−ln1−α0.24. Moreover, volume diffusion control with three dimensional growth of the nuclei was the predominant mechanism of crystallization. The simulation results confirmed that by employment of kinetic model, it was possible to control the microstructure as combination of amorphous/crystalline phases and enhance the saturation magnetization from 59 to 142 A·m2/kg and reduce the coercivity from 2.05 to 0.14 kA/m by controlling of crystallization progress at specific predefined α value.