Resumo

RODRIGUES, C. A. D.; KIMINAMI, C. S.; BOTTA, W. J.  e  TREMILIOSI-FILHO, G.. Resistencia al picado de Aleaciones Nanocristalinas de Al₉₀Fe₇Nb₃ y Al₉₀ Fe₇Zr₃obtenidas por Solidificación Rápida y Extrusión Caliente. Port. Electrochim. Acta [online]. 2009, vol.27, n.3, pp.309-316. ISSN 0872-1904.

Amorphous and/or nanocrystalline Al-based alloys have better mechanical properties when compared with crystalline conventional Al-alloys. Different techniques can be used to obtain amorphous Al-based alloys, usually in a ribbon form (from melt-spinning processing) or powders (from gas atomization or ball milling processing). To obtain bulk samples, that is, samples with dimensions typic ally much larger (mm scales) than the ones obtained from the above mentioned techniques (<40 mm), the ribbons or powders must be hot-consolidated. One of the most important challenges in the development of such alloys is to keep a refined microstructure after the necessary heating. The present work focuses the pitting resistance by electrochemical corrosion resistance test in solution 0.9 % NaCl and pH 7.0, for Al₉₀Fe₇Nb₃ and Al₉₀Fe₇Zr₃ nanocrystalline alloys, which were obtained by hot-extrusion of mechanically alloyed powders, and melt-spinning process. The results of the polarization curves indicated that the Al₉₀Fe₇Nb₃ and Al₉₀ Fe₇Zr₃ ribbons present better corrosion properties than the extruded alloys.

Palavras-chave : aluminum mechanical alloying; nanostructured powders; hot extrusion; melt-spinning; corrosion resistance.

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