Hot ductility behaviour of Al-Li alloy AA2091-T3

Abstract

The hot ductility behaviour of the AE-Li alloy 2091-T3 was investigated using hot ductility testing of the simulated heat affected zone (HAZ) using a Gleeble 1500 machine. Alloy 2091 displayed lower ductility, greater susceptibility to HAZ cracking, and poor ductility recovery on cooling from the nil strength temperature, compared with alloy 2219. Optical metallography and electron microscopy revealed that the ductility loss was accompanied by fracture transition front ductile transgranular mode to brittle intel granular mode. It was found that the HAZ intergranular liquation cracking was caused by non-equilibrium eutectic melting of T-2 phase precipitated at grain boundaries. (C) 1997 The Institute of Materials.