Fatigue Properties Of Additively Manufactured AlSi10Mg – Surface Treatment Effect

Abstract

Space industry strives to constantly increase performance and reduce costs of space missions. When dealing with producing space components, Additive Manufacturing (AM) is seen as a game changing technology also towards these goals. The applicability of this technology has already been demonstrated for space products and parts are currently flying. However, further studies are still needed to better understand the process parameters-final properties relationship.With this aim, a cooperative R&D activity was designed by EOS, RUAG and ESA, in order to characterise the fatigue behaviour of AlSi10Mg processed via AM. This activity comprised the study of the influence of building direction, platform temperature, powder layer thickness, surface finish and heat treatment on the fatigue properties of the AM specimens. As a complementary assessment, the defect population of the samples was studied through X-ray Computed Tomography (XCT).Results showed that there is a direct correlation between the process parameters and the fatigue properties of AlSi10Mg parts, having received the same post processing. Observations indicate that changing the parameters influences the characteristics of the defect population, determining the fatigue life of the specimens. In addition, the different surface finishing methods have, as expected, a strong impact on the fatigue behaviour of AM AlSi10Mg materials. This study shows that an optimised combination of process parameters and surface finish can improve fatigue performance, without the need for machining of the AM parts.