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A study of the amorphous-to-nanocrystalline transformation in Fe73.5Cu1Nb3Si13.5B9 through combined measurements of electrical resistivity, mechanical spectroscopy and TEM

1993; Elsevier BV; Volume: 3; Issue: 1-6 Linguagem: Inglês

10.1016/0965-9773(93)90110-w

1872-9150

Paolo Allia, Marcello Baricco, E. Bonetti, L. Del Bianco, P. Tiberto, Giovanni Valdrè, F. Vinai,

Theoretical and Computational Physics

Complementary information on the amorphous-to-nanocrystalline transformation in the Fe73.5Cu1Nb3Si13.5B9 alloy is obtained through electrical resistivity measurements, mechanical spectroscopy and analytical TEM. The temperature behavior of the dynamic Young's modulus M shows two softening stages at 480–510K and 770 K. The latter effect is associated with the onset of nanocrystallization, while the first anomaly is ascribed to a diffusion-segregation process for the minority elements. The resistivity vs temperature curves display a shallow dip at temperatures corresponding to the second softening stage of M. There, the isothermal resistivity relaxation displays a typical slowing down for certain temperature and time regions. Over an adjacent temperature interval, the dynamic-modulus kinetics appear to follow a stretched-exponential law with an exponent close to 0.8 and an activation energy E = 2.4 ± 0.1 eV. These results may be ascribed to crystal-growth inhibition mechanisms during the formation of the nanocrystalline phase.