Real-time monitoring of additive manufacturing alloys

Abstract

Metal-based additive manufacturing (AM) represents a paradigm change which will revolutionize the manufacturing across multiple industries such as the aerospace, biomedical and automotive sectors. However, today only a few alloys are compatible with AM. Most of those being used were developed for other manufacturing processes such as casting and forging processes where the mechanical properties can be controlled using thermal and thermo-mechanical processing, but not by the rapid solidification conditions of AM (steep heating and cooling rates between ˜ 103-108 ℃/s). In this context, the control of phase transformations and deformation modes in AM alloys plays a key role to obtain microstructures leading to suitable properties directly in the as-built state. This work uses real-time characterization at synchrotron facilities to reveal the influence of phase transformations on microstructure formation and reveal the activation of deformation mechanisms improving the strength-ductility trade-off. Titanium alloys fabricated by the powder-bed AM technique laser powder bed fusion (LPBF) are investigated using in situ synchrotron tomography and in situ high energy synchrotron X-ray diffraction. They are developed to tackle the drawbacks occurring in titanium alloys fabricated by AM, namely the formation of microstructures with anisotropy and poor ductility