Effect of Artificial Aging on Crack Resistance of Sheets of High-Strength Aluminum-Lithium Alloy V-1469

In this paper, we study the effect of artificial aging modes on the structure, mechanical properties, and crack resistance of high-strength aluminum-lithium alloy V-1469 sheets. Kinetic curves of changes in mechanical properties at various temperatures and long exposures are plotted. To establish the possibility of increasing the crack resistance, one-stage and multistage modes of artificial aging are selected in the study. As a result, a mode that allows increasing crack resistance at a slight decrease in strength and maintaining high corrosion resistance and fatigue life is chosen. The structural-phase state and the complex of properties of sheets processed according to the selected mode with sheets processed according to the mode providing maximum strength are compared. Crack resistance determined for large-sized (750 mm wide) samples from V‑1469T1 alloy sheets processed according to the selected aging mode is at the level of plating sheets of alloy 1163AT. Unlike high-strength aluminum alloys with strength and fracture toughness achievable by overaging, the same properties in aluminum-lithium alloy V-1469 can be achieved by aging with short exposures.