Differentiated fracture behaviors of a spray-formed Al-Cu-Li alloy under various heat treatments at liquid nitrogen temperature

Abstract

An experimental study was conducted on the tensile and fracture behaviors of a spray-formed Al-Cu-Li alloy at liquid nitrogen (LN₂) temperature. The mechanical properties and fracture morphology of the spray-formed, solution-treated and aged Al-Cu-Li alloy sheets at ambient temperature (AT) and −196 °C were discussed in detail. The tensile fracture behaviors at low temperature were revealed. It is illustrated that the stress gradient and limit strain at −196 °C are relatively larger due to a significant strengthening and plasticizing effect. The solution-treated and aged alloys present a large resistance to the plastic deformation and fracture at LN₂ temperature. The ductility of the aged alloy is insensitive to the LN₂ temperature. Compared to the aged alloy, the solution-treated alloy is more favorable for the forming and manufacture of complex-shaped Al-Cu-Li alloy components at low temperature of LN₂.