A benchmark activity on the fatigue life assessment of AlSi10Mg components manufactured by L-PBF
S. Beretta, L. Patriarca, Mostafa Gargourimotlagh, Alex Hardaker, David Brackett, M. Salimian, Johannes Gumpinger, T. Ghidini
Abstract
One of the challenges associated with additive manufacturing (AM) is the definition of an assessment route which considers the main process signatures of the AM process. To this end, this work presents a complete benchmark activity for the assessment of an AlSi10Mg component produced by a laser powder bed fusion process, aimed at advancing the understanding of the fatigue resistance of AM materials with particular focus on the comparison between the fatigue performances of small coupons and demonstrators. Four builds of AlSi10Mg specimen geometries were manufactured to: (i) determine the fatigue curves for both as-built and machined conditions; (ii) measure the fatigue crack growth rate; (iii) produce and test under fatigue a benchmark component used as a reference for the validation of the fatigue assessment procedure. Tools and concepts of flaw tolerance were then used to perform the fatigue assessment of the benchmark component and were shown to be successful in the life prediction. Results obtained from this wide database (related to internal defects and surface features) show that only a fracture-based fatigue assessment is able to provide precise life estimates consistent with material crack growth properties. Eventually, all the experimental results including specimens design, analysis of fracture surfaces and raw tests’ data will be made available in a database which can be accessed and used by the industrial and scientific communities to calibrate and validate alternative fatigue assessment procedures of AM parts.