Influence of aging on the impact fracture behavior of a RSP Al-Li alloy

Abstract

In recent years, there has been a growing interest in the development of Al-Li alloys for aerospace applications due to their high specific strength and elastic modulus. One important trend in manufacturing Al-Li alloys is the usage of rapid solidification processing (RSP), which offers several advantages over the ingot metallurgy methods. Therefore, it is a reasonable assumption that RSP Al-Li alloys have more satisfactory performance than their IM counterpart. The size of grains was indeed refined by RSP, but the tensile fracture mode of aged RSP Al-Li alloys was essentially intergranular fracture, and their ductility was even lower than that of the IM Al-Li alloys. The easily formed precipitation free zones (PFZs) in RSP Al-Li alloys area, the effect of microstructure on the impact fracture mode and on the impact properties of RSP Al-Li alloys is seldom studied. This paper investigates the influence of aging on the impact fracture behavior of a RSP Al-Li alloy, in order to explore its fracture mechanism upon an impact load, and the effect of prior powder boundaries on mechanical properties of the alloy.