Development of Aluminum-Lithium Alloys Processed by the Rheo Container Process

Abstract

This investigation describes the development and evaluation of thixoformable alloys on Al-Li-Mg basis in the scope of the collaborative research center SFB 289 at RWTH Aachen University. Scandium and zirconium was added to Al-Li2.1-Mg5.5 (A1420) with the aid of DoE (Design of Experiments) and precursor billets were manufactured by pressure induction melting (PIM). To evaluate the thixoformability of the synthesized alloys high-quality semi solid processed demonstrators were manufactured by the Rheo-Container-Process. Subsequent heat treatment raised the mechanical properties to maximum values of tensile strength of 432MPa, yield strength of 220MPa and an elongation of 13%. The RCP-Process was designed for the special requirements of this high reactive alloy. The paper will present extraordinary benefits in terms of properties and process simpleness for the semi-solid processing of Al-Li alloys.