Synthesis of nanocrystalline Ni3Fe powder by mechanical alloying using an extreme friction mode

• Nanocrystalline Ni3Fe synthesized by mechanical alloying – extreme friction mode.
• Our new approach is to fully fill the milling vials with milling balls (almost 100%).
• Mean crystallite size and lattice parameter evolution with the milling time.
• Influence of milling mode and time over the Ni3Fe powder magnetic properties.
• The shear forces are dominant in this mechanical alloying mode.

Extreme conditions for ball milling were created in order to have a complete friction mechanical milling/alloying mode: the vials were fulfilled with milling balls having almost 100% filling degree and so the shock collisions were avoided and the powder were processed only by mechanical energy transferred by friction. Nanocrystalline Ni3Fe powder has been obtained from elemental powders using the above mentioned specific conditions. The influence of friction mode on the formation of Ni3Fe intermetallic compound was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), particles size analysis and magnetic measurement. The Ni3Fe intermetallic compound was completely formed after 50 h of milling in this extreme friction milling mode and it is in nanocrystalline state with a mean crystallites size of 8 nm. The spontaneous magnetization increases by progressive formation of the Ni3Fe intermetallic compound, due to the iron magnetic moment enhancing by the Ni atoms vicinity.

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