The effect of the chemical composition on the mechanical properties of nanoquasicrystalline Al based alloys

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

Moscu

Congreso; IXX International Symposium on Metastable, Amorphous and Nanostructured Materials; 2012

Nanoquasicrystalline alloys composed by icosahedral quasicrystals embedded in and FCC Al matrix have the potential to push the applications of aluminium alloys to more elevated temperatures, by maintaining a high strength. Several previous reports in the literature show the importance of the chemical alloying to improve the thermal stability of these alloy systems. This stability in turn has a relevant effect on the mechanical properties. This work focusses on the study of the mechanical behaviour by tensile and compression tests of several quaternary nanoquasicrystalline alloys based alloys obtained by different processing methods including melt spinning, powder atomisation and followed by compaction and extrusion. Melt spinning has benn so far the most widely known way of obtaining these systems. Therefore materials have been obtained by melt spinning and in some cases followed by compaction and extrusion. The materials obtained this way were analysed in term of their chemical composition and their mechanical behaviour. On the other hand this study examines the production parameters of bulk nanoquasicrystalline Al-Fe-Cr –Nb/Ti alloys and alloys were produced in kilogram quantities through gas atomisation at an industrial scale. 0-25μm, 25-50μm and 50-75μm size fractions of atomised powder were each consolidated through extrusion to produce nanoquasicrystalline bars. The effects of the atomisation and extrusion conditions on the microstructure and its mechanical properties were studied. This reports compares the behaviour in strength and ductility with respect to the different alloying element s and Al composition. This analysis is doe comparatively for materials obtained through powder atomisation and melt spinning.