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Abstract: In this paper, the phase transformations occurring during the crystallization process of FINEMETs in which Nb has been gradually replaced by Mo have been studied by a variety of techniques including DSC, DTA, TGA, XRD and TEM. The thermal stability of the alloy was deteriorated as a consequence of Mo’s smaller atomic size. The gradual replacement of Nb by Mo reduced the onset temperature of Fe–Si and of the borides. The Curie temperature of the amorphous phase slightly decreased from 594K for x=0 to 587K for x=3. The borides compounds Fe2B and Fe23B6 as well as the (Nb,Mo)5Si3 phase were found to precipitate in the second and third crystallization. [Copyright &y& Elsevier]

Abstract: The crystallization of the as-quenched Fe76Mo8Cu1B15 ribbon proceeds in four independent transformation steps, which however mutually overlap both in the temperature and time scales. A complex thermokinetic method is presented, by which the individual transformations could be experimentally separated and characterized. The kinetics and mechanism of the individual transformations have been determined. Both linear-heating and isothermal differential scanning calorimetry was used. As-prepared as well as heat-treated samples were characterized by transmission electron microscopy, X-ray diffraction and Mössbauer spectroscopy. [Copyright &y& Elsevier]

Abstract: We present results of mechanochemical processing experiments performed on intermetallic powder, Al3Ti milled under hydrogen and helium atmospheres using a magnetically controlled Uniball device. Milling products were investigated by X-ray diffractometry (XRD), transmission electron microscopy (TEM) and advanced differential thermal analysis (DTA and DSC). Milling in both H2 and in He resulted in breakdown of the intermetallic structure and, after extended milling, formation of nanostructural products comprising, predominately, a solid solution of Ti in fcc Al, with some possible additional Al1+x Ti1−x (x =0.3) phase. Detailed kinetic analysis was preformed on the Al3Ti sample milled for 6days in hydrogen. Under isothermal annealing, the crystallization of the Al5Ti2 was found to follow the JMA kinetics, with constant activation energy E ∗ and Avrami exponent n decreasing from 2.5 to 1.5. [Copyright &y& Elsevier]

Amorphous Fe 78 Sn 5 B 17 ribbons were prepared by planar flow casting. The thermodynamic stability and the kinetics of observed phase transformations were monitored by thermal analysis. The structure and morphology of phases forming upon the thermally activated crystallization is studied by X-ray diffraction and transmission electron microscopy. The crystallization begins by nucleation-and-growth of specific nanocrystalline bcc-Fe(Sn) phase, its structure is explored more in details and the role of Sn in its formation is discussed. In the next step of the crystallization a transformation of remaining amorphous matrix to iron borides runs via rather complex process, which is inspected more in details as well. [ABSTRACT FROM AUTHOR]