Emerging trends in mechanical properties of Al-Li-X alloys

Abstract

Increasing interest of lightweight, high specific modulus Al-Li alloys in aerospace industries has developed a multi-element Al-alloys to induce precipitation hardening by tri-metallic compositions. Ductility and fracture toughness have remained unsolved in these alloys. Existence of tramp elements/impurities elements at the commercial scale alloys, from either low melting inter-granular sprayed-solidified have linked off weakness or harder grain boundary precipitations. However, precipitate free zone (PFZ) width in aged specimens has appeared to lessen the weakening effects. Of various combinations of aluminum lithium alloys in most cases illustration have been found about δ’, T1, S’, etc. precipitation. Variation of their appearance, size, volume fraction based on composition have showed conventional characterization in the alloy systems. 8090, 2090 type of alloy systems have treated highly acceptable than simpler binary and ternary compositions. Even with reference to globally accepted 2000 and 7000 series of aerospace aluminum alloys, 8090 has performed better except fracture toughness properties. Often this extra performance has expressed by existences of shearable - non-shearable precipitates existence on variation of treatment conditions and exposure conditions. Aim of this paper is to study mechanical properties of Al-Li alloy systems.