Tensile properties of an Al-Li-Mg-Zr alloy at cryogenic temperature

This study examines the tensile properties and fracture characteristics of an Al-Li-Mg-Zr alloy over the range 295-77 K. At various aging conditions, except the overaged one, both the strength and elongation improve. For the underaged and peak-aged specimens, there are a number of intergranular splittings (delaminations) which are deeper and more frequent at 77 K. The main effect of the decrease of the test temperature is the increase in the degree of intergranular splitting observed on the fracture surface. Although the delaminations in the overaged specimen broken at 77 K are more numerous than those at 295 K, the elongation decreases with decreasing test temperature because of the change in the cracking mode. 14 refs