Nanocomposite formation in Zr-Al-Cu-Ni-Fe amorphous alloys

M. A. BAB; L.C. DAMONTE; L.A. MENDOZA-ZÉLIS

Madrid, España

Simposio; International Simposium on the Industrial Applications of the Moessbauer Effect; 2004

Zr-Al-Cu-Ni-Fe belongs to the best glass forming systems known, these glasses present a high thermal stability and are suitable as precursor material for nanocomposites containing a variety of particles. At this respect, the presence of a second phase embedded in the amorphous matrix improves their mechanical properties, such as hardness and yield stress, as compared with single-phase amorphous alloys. On the other hand, the influence of the second phase particles on the extension of the supercooled liquid can be used to enable the warm-working of the bulk alloy to a desired shape, which is important for practical application. Ball milling has already demonstrated to be a valuable processing route for producing amorphous matrix nanocomposites, allowing to by-pass most of the limitation inherent to the casting techniques. In this work we present results on the formation, structure and thermal stability of nanocrystalline nitrides particles with fcc-Ti2Ni type structure dispersed in a Zr-Cu-Al-Ni-Fe amorphous matrix. The nitriding formation was performed by high-energy ball milling of Zr64Al7Cu17Ni10Fe2 amorphous ribbons in nitrogen atmosphere. The resulting nanocomposite structure was studied by Mössbauer spectroscopy and x-ray diffraction. Their thermal behavior was analyzed by differential scanning calorimetry, showing an increase in the thermal stability of the amorphous matrix by the composite formation.