Anodic Behaviour of Fe73,5Si13,5-xAlxB9Nb3Co1 (x=0, 1, 2) Amorphous, Nanostructured and Crystalline Alloys

M. G. ALVAREZ, S. M. VAZQUEZ, J. MOYA, H. SIRKIN

SCRIPTA MATERIALIA

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2001 vol. 44 p. 507 - 512

1359-6462

The development of nanostructural alloys has led to a significant improvement of soft magnetic materials (1). One of the most prominent examples is nanocrystalline FeSiBNbCu alloys. Owing to the formation of nanocrystallites embedded in an amorphous matrix, the magnetic anisotropy is substantially reduced and the magnetostrictive effects are eliminated (2). The magnetic properties and structural changes of FeSiBCuNb alloys have been studied extensively (2? 6). Owing to the widespread commercial utilisation envisaged for nanostructured materials, also the corrosion performance of FeSiBCuNb nanocrystalline alloys must be evaluated. In the present work, a comparative study of the corrosion behaviour of Fe73.5Si13.5B9Cu1Nb373.5Si13.5B9Cu1Nb3 amorphous, nanocrystalline and crystalline alloys in a chloride containing solution has been performed by means of electrochemical techniques. The influence of the microstructural changes caused by primary and secondary crystallisation on the polarization behaviour of the amorphous alloy was examined. The effect of the partial replacement of silicon by aluminium (1% and 2% Al) on crystallisation and corrosion behaviour has also been analyzed.