Thermal evolution of Fe65Ni20Nb6B9 nanocrystalline metastable alloy

P. MENDOZA ZÉLIS; C. E. RODRIGUEZ TORRES; F. A. CABRERA; M. B. FERNÁNDEZ VAN RAAP; G. A. PASQUEVICH; F. H. SÁNCHEZ; A. GONZALEZ; J.J. SUNYOL

Foz do Iguaçu-Brazil.

Simposio; 10th International Symposium on Metastable, Mechanically Alloyed and Nanocrystalline Materials; 2003

The alloy Fe65Ni20Nb6B9 was obtained from the elemental constituents in a high-energy planetary ball mill and was studied by 57Fe Mössbauer effect spectroscopy, Mössbauer thermal scans and X­ray diffraction. The as prepared nanocrystalline alloy consisted primarily of metastable bcc a­Fe(Ni) nanocrystals (57 nm mean size) and small amounts of g-(Fe,Ni) with Ni concentration of about 58%. Up to about 693 K only defect recovery is inferred. Between 693 and 873 K the a­phase transformed gradually into the fcc g-phase, whose starting Ni concentration decreased continuously with increasing temperature, reaching a final value which was below 32 at. %.