Abstract
This study investigates the influence of mean stress and material anisotropy (specimen orientation) on the high-cycle fatigue (HCF) behavior of a simulated recycled 6082 Al alloy designed as three variants (GA1, GA2, and GA3) with increasing trace element content (Fe, Cu, and Zn). Specimens were extracted along transverse and longitudinal directions relative to extrusion. GA3 (with the highest trace element content) exhibits inferior fatigue performance compared with GA1, with a higher mean stress sensitivity in the former case. This is attributed to the varying influence of intrinsic factors like surface roughness and slip character, along with extrinsic factors like load-level variations. For GA3, longitudinally extracted specimens show longer fatigue life and lower mean stress sensitivity than those extracted transversely. Differences in fatigue life and mean stress sensitivity between specimen orientations are found to be primarily governed by intrinsic factors, like microstructure (grain size distribution, slip character) and surface roughness, rather than changes in load levels.