Electrical Conductivity Variations in X2096, 8090, 7010 and an Experimental Aluminium Lithium Alloy

The alloy X2096 (Al-Cu-Li-Mg-Ag) is a low-density high strength structural alloy designed to achieve the strength of 7075T6 combined with the SCC resistance of 7010/7050T74 without the necessity for cold working after solution heat treatment. The alloy is weldable with forging, plate, and extrusion applications. The composition of this alloy has been optimized for the maximum lithium content without forming delta prime. There is evidence that the electrical conductivity of X2096 does not follow an expected pattern during heat treatment. An air-cooled homogenized ingot of X2096 displayed a conductivity of 16 pct IACS, but when solution heat-treated, the conductivity was noted to increase to 18 pct IACS. The electrical conductivity and Vickers hardness of this alloy has been determined after both isothermal and isochronal heat treatments and compared to 8090, a new next generation experimental Al-Li alloy and the Al-Zn-Mg-Cu alloy 7010. The hardness and conductivity variations of X2096 are reported and correlated with microstructural observations. (Author)