Development of Fe based materials obtained by mechanical alloying

Fe rich alloys with ZrNi or Nb and with non metallic B were developed by means of mechanical alloying. The material is nanocrystalline with a minoritary amorphous phase (about 12%). The reduction of the crystallite size is favoured by the addition of Zr, Nb or B. The mechanical alloying parameters were optimised to obtain a nanocrystalline state at low milling time. Furthermore, the apparent activation energy of the crystallisation processes was obtained by thermal treatment, controlled by differential scanning calorimetry. Typical values between 280 and 410 kJ mol(-1) are associated to crystalline growth. The control of the crystal size is related to the kinetic study of the non-equilibrium transformations where the incipient phase as different composition that the initial phase.