Chapter 1. Brief history of aluminum-lithium alloy creation -- Chapter 2. Theoretical basis of aluminum-lithium alloying with controlled lithium content and metallic and nonmetallic impurities -- Chapter 3. Hydrogen in aluminum-lithium alloys -- Chapter 4. Crack susceptibility and peculiarities of casting aluminum-lithium alloy billets -- Chapter 5. Aluminum-lithium alloy grain structure solidification conditions and peculiarities -- Chapter 6. Excess hetero-phasicity in 1420 alloy billets and its hereditary influence on the structure, properties, and weldability of semifinished products -- Chapter 7. Structure, mechanical properties, and weldability of alloy 1420 die forgings of complicated configuration versus initial slab structure and pressure-forming modes -- Chapter 8. Aluminum-lithium alloy welding process features.