Following the pioneering patent of Wiley on Al-Sc alloys (1971), an extensive research program has started in the USSR in the 1970s, dedicated both to the fundamentals of interaction and mechanisms of Sc in Al and to the development of Sc-containing aluminum alloys. A number of very important phase diagrams of practically important systems have been experimentally studied and laid the foundation for the development of wrought and casting alloys with Sc. The unique equilibrium L12 Al3Sc phase has been characterized and its role in grain refinement, precipitation hardening and preventing recrystallization has been identified and explained. Interaction of Sc with other transition elements, in particular Zr, has been investigated. A number of alloys of Al-Mg, Al-Li-Mg, Al-Zn-Mg, Al-Cu systems with particular properties, e.g. high strength, weldablity, superplasticity, have been developed and commercialized in the 1980-1990s.
This presentation gives an overview of those developments.