INTECIN   20395
INSTITUTO DE TECNOLOGIAS Y CIENCIAS DE LA INGENIERIA "HILARIO FERNANDEZ LONG"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Icosahedral Order in Rapid Solidified Al-Fe based Alloys
Autor/es:
F. AUDEBERT; M. GALANO; F. SAPORITI; P. QUINN
Lugar:
Sao Carlos
Reunión:
Congreso; V latin-american conference on nanostructured and metastable materials; 2012
Resumen:
Rapid Solidified (RS) Al-based alloys can be obtained with several types of microstructures which combine amorphous, crystalline or/and quasicrystalline phases. Therefore, it is possible to obtain alloys with an excellent combination of properties, like high strength and toughness with good corrosion behaviour. Alloys with these characteristics have great potential for technological applications. The microstructure of these alloys is mainly controlled by nucleation process during the rapid solidification. Therefore, the chemical composition is a key factor for the microstructure and properties obtained in the RS Al-based alloys. Al-Fe and Al-Ni based alloys have been studied with a combination of experimental and modeling techniques, for instance Mössbauer Spectroscopy, XRD, EXAF, TEM and Molecular Dynamic Simulation. The cluster analysis at the liquid and the under-cooled liquid states show that Al-Fe alloys contain higher volume fraction of icosahedral clusters than the Al-Ni alloys. Also, it was observed that Niobium and Chromium improve the stability of the Al-Fe icosahedral order. The study of the local order in the melt and the influence of several elements on the microstructure of RS Al-based alloys allowed to design amorphous and nanoquasicrystalline Al-Fe based alloys with high thermal stability and good combination of properties. Mechanical properties and corrosion behavior have been studied, and it is observed that Al-Fe-Nb RS alloys have high potential for being used as surface material for tribology applications and the Al-Fe-Cr-Nb RS alloys for being used as structural material for elevated temperature applications.