Transition Element Modifications of Al-Li

The development of aluminum-lithium metallurgy has led to alloys with unsurpassed combinations of density, specific strength, and specific modulus. This paper describes recent advances in the modification of aluminum-lithium binary alloys through additions of the Group IV-A transition metals (titanium, zirconium, and hafnium). These elements lead to a duplex precipitation hardening behavior through the formation of Al3Li and Al3(TM,Li) (TM = transition element) which act as strengthening precipitates. The influence of the duplex structure on deformation mechanisms and the improvement of mechanical properties in these systems is illustrated by using results for the Al-Li-Zr system. 12 references.