Influence of as-built surfaces on the fatigue behavior of AlSi10Mg parts obtained by laser powder bed fusion

In the recent years the industrial expectations about metal additive manufacturing technology have exploded with an increasing focus on materials and components qualification. Qualification and certification of L-PBF components for structural application require an understanding of the links among technology, materials and fatigue performance. One dominating factor affecting fatigue strength is the as-built surface quality of the -PBF parts because surface modification would add unacceptable high costs is impossible due to geometrical complexity. The present contribution, being aimed at L-PBF applications for the automotive and aerospace sectors, deals with the AlSi10Mg alloy, the most relevant and studied Al-alloy, produced with an industrial grade L-PBF system operated by an established AM service provider. The overall objective was the determination of the link between the as-built surface quality, i.e. technology-dependent, and the fatigue data required for the structural integrity assessment of L-PBF parts. An innovative fatigue test methodology using a miniature specimen geometry was applied to the efficient investigation of L-PBF technology-dependent factors on the fatigue behavior of AlSi10Mg alloy.