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...
A study of the amorphous-to-nanocrystalline transformation in Fe73.5Cu1Nb3Si13.5B9 through combined measurements of electrical resistivity, mechanical spectroscopy and TEM
DEL BIANCO, Lucia;
1993
Abstract
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...I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
