Nanocrystalline Nitrides in Amorphous Matrix

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

Foz do Iguazu

Congreso; II Worshop of the Metastable and Nanostructured Materials; 2003

The formation of metallic nitrides and hydrides by milling in gaseous (N2,H2) ambient is dicussed. The reaction kinetics and its dependence on composition and structure are analyzed. The aplication of this method to the formation of nitride precipitates in amorphous matrixes is considered. Melt- spun Zr64Al7Cu17Ni10Fe2 amorphous ribbons were milled under nitrogen atmosphere for different times. The resulting powders were studied by x-ray diffration, Mössbauer spectroscopy and differential scanning calorimetry. The formation of nanosized crystalline particles, with cubic ZrN structure, dispersed in the amorphous matrix was observed along with a change in the composition of the amorphous phase. Prolonged milling leads to the additional precipitation of late transition metals (Fe, Ni and Cu).The effect of the nitride particles on the crystallization behavior of the amorphous alloy is discussed.