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

In this paper, the interactive influences of notch severity and test temper ature on the impact properties and fracture behavior of a AI-Cu-Mg alloy 20 24 in the T351 microstructural condition is presented and discussed, Notch angles of 45, 60, 75, and 90 degrees were chosen for a standard Charpy impa ct test specimen containing two notches. For a given angle of the notch, an increase in dynamic fracture toughness, with test temperature, is most sig nificant for the least severe of the notches, i.e., 45 degrees, 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 failur e at all test temperatures. The influence of localized mixed-mode loading i s minimal for the alloy in the T351 microstructural condition. The impart f racture behavior of the alloy is rationalized in light of alloy microstruct ure, mechanisms governing fracture, and the deformation field ahead of the propagating crack.