After Concorde: evaluation of creep resistant Al-Cu-Mg-Ag alloys

A European consortium is evaluating materials for the construction of a new supersonic transport ail cl aft that may replace Concorde. Current designs propose to use art aluminium alloy for the fuselage which is required to have superior creep resistance and damage tolerance to the Concorde alloy 2618A. Promising results have been obtained with excluded Al-Cu alloys containing minor additions of magnesium and silver which stimulate hardening by the relatively stable Omega precipitate. Data is presented which shows that these alloys have tensile and accelerated creep properties which are better than those of competing commercial alloys of the 2000 series, together with satisfactory levels of fracture toughness. Of the four experimental alloys studied, the optimal composition is Al-5.6Cu-0.45Mg-0.45Ag-0.30Mn-0.18Zr (wt-%). MST/4224.