The best aluminium alloy system with regard to elevated temperature properties (250 C to 300 C) was selected. Tensile and creep properties at temperatures up to 350 C, fracture toughness and corrosion behaviour of extruded bars in 11 alloys from the aluminium iron vanadium, aluminium iron molybdenum, aluminium chromium nickel and aluminium manganese nickel systems fabricated by hot consolidation of gas atomized powders have been studied. The stability for long exposures at temperatures up to 300 C of all these alloys has been demonstrated on the basis of fine microstructural investigations and mechanical tests. However, it has been clearly established that the aluminium iron vanadium alloys present by far the best compromise in terms of strength, creep resistance and fracture toughness.
Attempts have been made to optimize the chemical composition of the aluminium iron vanadium alloys and the fabrication process in order to maximize the compromise between mechanical properties and manufacturability. The cross effect of the iron content and the powder size distribution and the effect of magnesium additions have been studied in the case of the gas atomization process. In parallel rotating electrode, melt spinning and mechanical alloying techniques have been investigated and compared to gas atomization. This task resulted in the selection of 2 chemical compositions, aluminium iron vanadium (Al-6Fe-1.5V) and aluminium iron vanadium magnesium (Al-6Fe-1.5V-Mg), on the definition of recommendations for the manufacturing process and on the establishment of typical design properties.
Sheets and extruded bars in aluminium iron vanadium and aluminium iron vanadium magnesium have been fabricated on industrial equipment and extensively tested; the cost and technical analysis of potential applications have been carried out, confirming the strategic interest of these new materials, at least for aerospace applications, and proposals for further developments with the objectives of cost reduction and increased reliability have been made.
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