Since its introduction in the twenties, 2024 alloy has been used by aerospace designers for damage tolerance dominated structures. Thanks to its good balance between static strength and toughness, and despite its rather poor level of corrosion resistance, 2024 plates, sheets or extruded sections continue to be used as a low-cost baseline solution for lower wing panels and stringers or fuselage panels and stiffeners.

Over the last years, successful development activities were focused on improving either the damage tolerance or the strength level of the standard 2024 alloy, in an effort to reduce the weight of the DT dominated lower cover structures. However, improving both strength and DT was kept as a challenge: fabrication methods such as cold-working to achieve better strength lead to low spectrum crack growth resistance and manufacturing issues, and the low solute high purity chemistries used to higher DT do not allow any strength benefit.

The presentation will be focused on alloy AA2027 recently developed by Pechiney Aerospace for plates as well as for heavy and light section extrusions. It will be shown that the corresponding Zr-containing chemistry enables both strength and DT improvements versus reference material, without degrading other design or corrosion properties. 2027 alloy is being qualified to fly on various Airbus programmes.