E. Colvin, Alcoa Forgings and Extrusions, Lafayette, IN; L. Yocum, Alcoa Engineered Products, Lafayette, IN; D. Bush, Alcoa Forged Products, Cleveland, OH; R. J. Rioja, Alcoa, Inc., Alcoa Center, PA
Alcoa Forgings and Extrusions has developed and is introducing a new Al-Li alloy, designated C99N, with strength, toughness, fatigue and corrosion combinations exceeding previously available Li-containing products. The alloy is intended for high strength extrusion and forging applications to compete with advanced 7xxx alloys with improved resistance to SCC and exfoliation and significantly lower density and higher modulus of elasticity. The new alloy can save weight and improve durability of structures such as compression-dominated stringers and web-rib forgings. Alcoa is generating extrusion design allowables and has developed a set of preliminary forging properties.
