Fatigue strength of PBF‐LB/M and wrought 316L stainless steel: effect of post‐treatment and cyclic mean stress. Issue 11 (3rd August 2021)

• Record Type: Journal Article
• Authors: Braun, Moritz; Mayer, Eduard; Kryukov, Igor; Wolf, Christian; Böhm, Stefan; Taghipour, Aliakbar; Wu, Rachael Elizabeth; Ehlers, Sören; Sheikhi, Shahram
• Is Part Of: Fatigue & fracture of engineering materials & structures. Volume 44:Issue 11(2021)
• Page Start: 3077
• Page End: 3093
• Publication Date: 2021-08-03
• Subjects: additive materials -- heat treatment -- mean stress effects -- selective laser melting -- surface roughness -- surface treatment; Materials -- Fatigue -- Periodicals; Fracture mechanics -- Periodicals; 620.1123
• DOI: 10.1111/ffe.13552
• Languages: English
• ISSNs: 8756-758X

Abstract

Abstract: Additive manufacturing (AM) enables the cost‐effective production of complex components, many of which are traditionally manufactured using costly subtractive processes. During laser‐based powder bed fusion of metals (PBF‐LB/M), internal pores and rough surfaces are typically inevitable, reducing fatigue and corrosion resistance compared to traditional processes. Additionally, large defects often occur near to or at surfaces. Thus, this study investigates the effect of hybrid additive and subtractive manufacturing on the fatigue strength of AISI 316L. To this goal, different post‐treatment routes are compared with wrought material. Additionally, computed tomography is used to determine the necessary machining depth of the surface layer. In this study, heat treatment and machining are both found to significantly increase fatigue strength (17% and 87%). Finally, the mean stress sensitivity M of as‐built PBF‐LB/M and wrought material is found to be highly affected by the assessed number of cycles to failure and residual stresses in PBF‐LB/M material. Highlights: Analysis of influencing factors on fatigue of L‐PBF/M and wrought 316L stainless steel Comparison of fatigue and static strength of differently processed 316L Assessment of cyclic mean stress on fatigue of AM and wrought 316L Determination of necessary machining depth of the surface layer by computed tomography