Resumo

BONYUET, D et al. Synthesis and characterization of the mechanically alloyed Fe₄₀Ni₄₀Ag₂₀ and (FeNi)₈₀Ag₂₀. Rev. Fac. Ing. UCV [online]. 2006, vol.21, n.2, pp.53-60. ISSN 0798-4065.

Mechanical Alloying (MA) is a process that has shown to be a versatile tool to produce nanostructured composites and alloys from normally immiscible elements. It has the advantage that the parameters of the process can be varied in order to control the grade of the alloy and the microstructure characteristics. In this form, it is possible to produce magnetic materials with new properties. The phase diagrams of Ni-Ag and Fe Ag show that mutual solubility is very low in the liquid state as in the solid state. However, it has been able to obtain partial solid solutions in these systems by mechanical alloying and other techniques. Because the ball milling process is a non equilibrium technique, it is possible to force the mixture of immiscible elements. In this work we present a study of the ternary system Fe-Ag-Ni, preparing by mechanical alloying Fe₄₀Ni₄₀Ag₂₀ and (FeNi)₈₀Ag₂₀ in a SPEX 8000 mixer/mill. Then we characterized the samples by X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and Mössbauer spectroscopy. The nanometric size grain is confirmed by XRD. Mössbauer spectroscopy indicates the grade of alloying after different milling times.

Palavras-chave : mechanical alloying; immiscible systems; Fe-Ag-Ni system.