high-strength al li alloy with low density and high ductility at high temperatures

摘要

An aluminum-based alloy useful in aircraft and aerospace structures which has low density, high strength and high fracture toughness consists essentially of the following formula: CuaLibMgcAgdZreAlbal wherein a, b, c, d, e and bal indicate the amount in wt. % of alloying components, and wherein 2.8a3.8, 0.80b1.3, 0.20c1.00, 0.20d1.00 and 0.08e0.40. Preferably, the copper and lithium components are controlled such that the combined copper and lithium content are kept below the solubility limit to avoid loss of fracture toughness during elevated temperature exposure. The relationship between the copper and lithium contents also should meet the following relationship: Cu (wt. %)+1.5 Li (wt. %)5.4.