M. Abdellaoui et al., SUPERSATURATED A2 SOLID-SOLUTION INDUCED BY BALL-MILLING IN THE FE - SI SYSTEM - STRUCTURAL AND MAGNETIC CHARACTERIZATION AND THERMAL-STABILITY, IEEE transactions on magnetics, 30(6), 1994, pp. 4887-4889
Based on X-ray diffraction (XRD) pattern analysis and differential sca
nning calorimetry (DSC), we studied the far from equilibrium phase tra
nsitions induced by mechanical alloying (IMA) as well as the magnetic
properties of Fe - Si samples with 33 and 37.6 at % Si. Two high ball
milling (BM) shock powers are used in order to check the possibility o
f further expansion of the A2 crystalline disordered solid solution ph
ase domain. For the two studied compositions, BM induces the formation
of a mixture of the A2 crystalline disordered solid solution and an a
morphous phase. The A2 phase grain sizes, the A2 lattice parameter, an
d the amorphous phase crystallization activation energy are 3 to 7 nm,
0.285 nm, and 160 to 270 kJ mole(-1) for the 33 at. % Si composition
and from 3 to 7 nm, 0.284 nm, and 274 to 298 kJ mole(-1) for the 37.5
at. % Si composition. The influence of the structural state and the gr
ain size on the coercive force are studied. A coercive force of 2.288
kA/m at 600 Hz and 0.145 T was found for the 37.5 at. % Si composition
sample.