Mechanical Grinding of Iron Borides

RODRÍGUEZ TORRES, C.E.; SÁNCHEZ, FRANCISCO H.; MENDOZA-ZÉLIS, L.; FERNÁNDEZ VAN RAAP, M.B.

Materials Science Forum

SCIENTIFIC NET

Año: 1995 vol. 179 p. 103 - 108

The effect of mechanical grinding on FeB and Fe2B has been studied by Mossbauer effect spectroscopy and x-ray diffraction. In both cases, decomposition of the original phase was observed: FeB → FeB + Fe2B; Fe2B → α-Fe + B. In the case of Fe2B, strain initially grows and grain size reduces, increasing the system energy by an amount of the order of its formation enthalpy. Later, iron segregates while Fe2B crystalline size continues to diminish. A simple calculation suggests that the unmixed state may become energetically favorable under mechanical grinding refinement. The results observed in both systems admit an explanation based on a common kinetic description.