X-ray and differential scanning calorimetry study of the crystallization of amorphous Fe73.5 Cu1Nb3 Si13.5B9 alloy

The crystallization behaviour, the lattice parameters of the crystallized phase and the crystallization kinetics of amorphous Fe73.5Cu1Nb3Si13.5B9 alloy were investigated by X-ray diffraction and differential scanning calorimetry. When the alloy was annealed at above 480°C for 1 h, nanocrystalline Fe(Si) phase precipitated from the amorphous matrix. As the annealing temperature rose, the lattice parameter a0 of the Fe(Si) phase increased from 0.2838 nm to 0.2849 nm. At 600°C tetragonal Fe3B precipitated, and at 670°C f.c.c. Fe23B6. After pre-annealing above 400°C, the crystallization activation energy was raised significantly from 384 kJ Mol−1 to 494 kJ mol−1. During isothermal annealing the crystallization activation energy dropped from 520 kJ mol−1 to 360 kJ mol−1 as the annealing continued, while it increased appreciably with pre-annealing.