In-Situ Synchrotron X-ray Diffraction Study of Structural Evolution during Tensile Deformation of Direct Additive Manufactured 17 − 4 PH Steel

Additive manufacturing (AM) technologies are revolutionising the production of complex and customised components. Despite these geometric innovations, the microstructure of these ‘new’ materials has posed a major obstacle to the widespread adoption of these technologies in novel applications. However, understanding the microstructural evolution during mechanical loading is necessary to elucidate the mechanisms and implications of using AM 3D objects in critical applications. This study uses in-situ synchrotron X-ray diffraction (XRD) during tensile testing to clarify the deformation mechanisms and microstructural transformations in additively manufactured 17 − 4 PH stainless steel (AISI 630). Controlled tensile loading was applied to the tensile specimens, enabling the simultaneous capture of XRD, thereby providing real-time insights into material response. The analysis highlighted the structural evolution and phase transformations occurring during deformation, providing a deeper understanding of the underlying mechanisms that influence the unique mechanical properties resulting from Laser Powder Bed Fusion (LPBF). The results demonstrate a clear correlation between microstructural attributes and mechanical performance, contributing to optimising the design vs. properties. Graphical Abstract: (Figure presented.)