The impact fracture behavior of aluminum alloy 2024-T351: Influence of notch severity

In this paper, the interactive influences of notch severity and test temperature on the impact properties and fracture behavior of a Al-Cu-Mg alloy 2024 in the T351 microstructural condition is presented and discussed. Notch angles of 45, 60, 75, and 90° were chosen for a standard Charpy impact test specimen containing two notches. For a given angle of the notch, an increase in dynamic fracture toughness, with test temperature, is most significant for the least severe of the notches, i.e., 45°. At a given test temperature, the impact toughness decreased with an increase in notch severity. An increase in notch severity resulted in Mode I dominated failure at all test temperatures. The influence of localized mixed-mode loading is minimal for the alloy in the T351 microstructural condition. The impact fracture behavior of the alloy is rationalized in light of alloy microstructure, mechanisms governing fracture, and the deformation field ahead of the propagating crack.