Crystallization and soft magnetic properties of metalloid-free Fe89Hf7Al3Zr1 amorphous alloy

A new high iron content metalloid-free Fe-based amorphous alloy with the nominal composition of Fe89Hf2Al3Zr1 was fabricated by melt-spinning technique. The alloy shows good soft magnetic properties, such as saturation induction B-s up to 1.60 T and coercivity H-c as low as 43 A/m. Crystallization was investigated in non-isothermal conditions using DSC measurements. It was shown that the observed DSC peaks may be attributed to precipitation of alpha-Fe phase and Fe2Hf(Zr) compound, respectively. The apparent activation enthalpy E-p of both the exothermic peaks was determined by Kissinger and Ozawa models. The local activation enthalpy E(x) decreases gradually with crystallized volume fraction x indicating that crystallization process of the second step becomes easier. After annealing at different temperatures, the B-s maintains a trend of increase in each crystallization process. The optimized annealing process is established at 798 K (close to T-p1) for 0.5 h with maximum B-s of 1.75(+/- 0.01) T. (C) 2017 Elsevier B.V. All rights reserved.