Al-Fe-Cr BASED QUASICRYSTALLINE NANOCOMPOSITES

M. GALANO; F. AUDEBERT; W. GU; N. ROUNTHWAITE; G. W. SMITH

Beijing

Congreso; ISMANAM 2009 - XVI International Symposium on Metastable, Amorphous and Nanostructured Materials; 2009

In the recent years a new generation of Al based alloys have emerged comprising of nano-quasicrystalline particles embedded in an alpha-Al matrix. These alloys have proven to have a high strength in comparison with commercial Aluminium alloys at room and in particular alloys within the Al-Fe-Cr-Ti system produced by melt spinning showed high strength at elevated temperatures elevated temperatures.In early works, it was observed that the substitution of Ti by Nb increased the stability of the quasicrystalline phase delaying the microstructural transformation to higher temperatures. Thus, these nanocomposites containing Al-Fe-Cr-Nb quasicrystals have become promising new high strength nanocomposites to be applied at elevated temperatures in the automotive and aeronautical industries. Extruded bars from atomised powder of different alloy compositions such as Al-Fe-Cr-Nb and Al-Fe-Cr-Ti have been produced. Also, different mixtures of atomised pure aluminium and nanoquasicrystalline powders were used to produce bulk material. The microstructure of the atomised powders and extruded bars was characterised by means of XRD, SEM, TEM, and EDX and DSC. Mechanical properties have been studied by means of microhardness and compression tests. The relationship between processing, microstructure and properties is being discussed. The extruded bars maintained good mechanical properties similar to the reported for the as melt spun ribbons, thus, offering a feasible alternative for industrial applications.