New high toughness aluminum-copper-lithium alloy

Aluminum Canadian company Alcan Rhenalu invents an Al-Cu-Li alloy with a high fracture toughness to produce thin- and light-gauge plates. It was patented in the United States. Patent No. US7744704B2. Alloy composition (w%): 2.7-3.4Cu, 0.8-1.4Li, 0.1-0.8Ag, 0.2-0.6Mg, at least one of the following components: 0.05-1.3Zr, 0.05-0.8Mn, 0.05-0.3Cr, 0.05- 0.3Sc, 0.05-0.5Hf, 0.05-0.15Ti, and the rest are aluminum and unavoidable impurities. The content of copper and lithium should maintain the following relationship: (Cu+5/3Li)<5.2. The ingot is uniformly annealed at 490-530°C for 5-60 h. The ingot is rolled into a thin plate and a middle plate with a final thickness of 0.8-12 mm; the plate is stretched by 1%-5%; the plate aging system is 140-170° C./5-30 h.