Characterization and Depth Profile of Lithium Depletion in Aluminum-lithium Alloys by Ultrasound

Aluminum-Lithium (AI-Li) alloys have been developed as an alternative to conventional aluminum alloys for use in aerospace and other applications where lowweight, high strength materials are required. The use of Al-Li alloys in military and civil air transport continues to increase [1]. The key benefits of AI-Li alloys, when compared to conventional aluminum alloys, are the lower density and higher elastic modulus. Thus, AI-Li alloys offer enhanced mechanical properties while decreasing overall weight. This is crucial for high performance aircraft, where the higher strength-to-weight ratio can give considerable velocity and maneuverability advantages. It is also of significant benefit for transport aircraft and spacecraft, where reduced weight will increase the range and lift capability, especially if operating at supersonic velocities with large loads. The improved efficiency increases the feasibility of developing a supersonic civil transport that can successfully operate within the economic restrictions of the commercial marketplace.