Evaluation of Small-Scale Thin Wall AlSi7Mg Alloys LPBF Coupons under Extreme Low Cycle Fatigue Regime †

Abstract

The recently developed process of additive manufacturing of aluminum alloys via laser powder bed fusion (LPBF) has the capability to build parts with complex geometries, which can lead to potential benefits in manufacturing industries. The adoption of intricate thin wall structures is restrained by the lack of reliable mechanical property data and understanding of the failure sequence in extreme cyclic loading conditions. The results show that the LPBF AlSi7Mg thin-walled specimens under an Extreme Low Cycle Fatigue (ELCF) regime for 0.1 mm to 0.8 mm design thin wall thickness variation attained results of 1 to 20 number of cycles to failure (Nf) in as-built, stress-relieved annealing and T5 heat treatment conditions. The present work also explores the factors linking GD&T, and heterogeneity of the thin-walled alternate cyclic bend fatigue-tested specimens.