INVESTIGADORES
GALANO Marina Lorena
congresos y reuniones científicas
Título:
Atomised Nanostructured Al-Fe-Cr-Based Alloys
Autor/es:
FERNANDO AUDEBERT; MARINA GALANO; CARLOS TRIVEÑO RIOS; H KASAMA; C BOLAFARINI; C KIMINAMI; W BATTA FILHO
Lugar:
Varsovia
Reunión:
Simposio; Ismanam 2006; 2006
Resumen:
Nanostructured Al-based alloys exhibit high strength in comparison with commercial
Aluminium alloys. Several kinds of nanostructured Al-based alloys were produced by rapid
solidification processes. Particularly Al-Fe-Cr based alloys produced by melt-spinning were
obtained with a microstructure composed of nano-quas icrystalline particles embedded in an
α-Al matrix. These alloys exhibited high strength at elevated temperatures; nevertheless, the
quasicrystalline particles in these systems become unstable at high temperature limiting the
industrial applications. In early works, it was observed that the use of Nb or Ti increase the
stability of the quasicrystalline phase delaying the microstructural transformation to higher
temperatures [1,2]. Thus, these nano-quasicrystalline Al-based alloys have become promising
new high strength alloys to be applied at elevated temperature in the automotive and
aeronautical industries. The nano-quasicrystalline Al-Fe-Cr-based alloys were mostly
obtained by rapid solidification using the melt-spinning technique. In order to obtain bulk
alloys for industrial applications new fabrication routes such as powder atomisation followed
by extrusion are required.
In the present work, four Al-Fe-Cr-based alloys containing Nb and different Fe/Cr ratios were
produced by powder atomisation. A small fraction of Ti was added to one of the alloys and in
addition a small fraction of Si was added to two of them aiming to analyse the influence of the
chemical composition on the microstructure of the atomised powders. The powders obtained
were seeded in different ranges of sizes between 25 and 250 μm and the microstructures were
characterised by means of X-ray diffraction, scanning electron microscopy, energy dispersive
X-ray spectroscopy and transmission electron microscopy. The microstructure and the
different phases obtained are discussed in relation to the chemical composition and the
powder size ranges.