Extreme low cycle fatigue behavior comparison between LPBF and wrought Al7SiMg alloys for small-scale specimen

Additive Manufacturing (AM) processes, which include Laser Powder Bed Fusion (LPBF), enable us to fabricate metals parts with an unmatched degree of freedom through a layer-by-layer approach. LPBF components should operate under varying loading conditions from static to extreme dynamic loadings. However, due to heterogeneities and geometrical variations within LPBF parts, reliability issues, especially fatigue behavior of small-scale components, can be observed. This research work proposes a methodology to study Extreme Low Cycle Fatigue (ELCF) regime (N_f < 100) for small-scale cylindrical/ thin walls having a diameter/ thickness of ≤1mm. This study compares the key factors influencing fully reversed strain-controlled loading ELCF of LPBF Al7SiMg alloy with wrought counterpart. This work is linked with the Cyclic Void Growth Model (CVGM) for fatigue life estimation.