Influence of Shot Peening on Fatigue Performance of High-Strength Aluminum - and Magnesium Alloys

Author:  Dorr, Hilpert, Beckmerhagen, Kiefer, Wagner
Source:  Conf Proc: ICSP-7 (pg 153-160)
Doc ID:  1999025
Year of Publication:  1999
Abstract:  
Shot peening was performed on 2024 Al and the magnesium alloy AZ 80 using various peening media (cast steel, spherically conditioned cut wire, ceramic and glass beads) and various Almen intensities. Fatigue performance of both alloys was found to depend mainly on Almen intensity, independent of the particular peening medium. While the fatigue life of 2024 Al strongly increased with Almen intensity and then reached a saturation value, the magnesium alloy showed a pronounced overpeening effect, i.e., a marked fatigue life improvement at low Almen intensities followed by a severe drop in fatigue life as Almen intensity increased. The results are explained in terms of the sensitivity of the different materials to surface damage affecting both fatigue crack nucleation and microcrack propogation.