College of Engineering
Materials Engineering Department
BS in Materials Engineering
2219 aluminum has been used extensively in aerospace applications due to its ability to retain strength in large section thicknesses, thus making it ideal for large forgings. However, the Metallic Materials Properties Development and Standardization (MMPDS) handbook, a source of design data for aerospace industry applications, lacks information on 2219 in the T852 condition, particularly concerning the behavior of the alloy under cyclic loading conditions. Data was collected for forgings of 2219-T852 aluminum as produced by Weber Metals to determine the fatigue life of the alloy-temper combination and to assess the effects of forge thickness and orientation on fatigue life. The samples tested were taken from the longitudinal (L) and short transverse (ST) orientations of 8″ and 12″ thick open die forgings of 2219-T852. Rotating beam fatigue tests were conducted on polished samples under a fully reversed stress condition, with stress levels ranging from 20 to 45 ksi. The applied stresses were plotted against the number of cycles to failure to generate stress-life (S-N) curves for each orientation and thickness combination. 8″ and 12″ thick ST samples were found to have comparable fatigue lives, while the ST samples exhibited a higher fatigue life than L-oriented samples. Scanning Electron Microscopy was used to characterize the fracture surfaces, with many pronounced beach marks on samples that were subject to lower stress levels relative to samples tested at higher stress levels.