In Situ Synchrotron and Neutron Characterization of Additively Manufactured Alloys

Additive manufacturing (AM) of metals and alloys represents a suite of emerging manufacturing processes that fabricate parts layer-by-layer following a three-dimensional digital model. Since its inception, AM has proven effective for concept modeling and rapid prototyping, and during the last decade, has started to realize its revolutionary potential to impact the manufacturing industry for the production of customizable, high-value parts with complex shapes and geometries in, e.g., the aerospace, automotive, medical, and military sectors. [...]barriers include limited in situ monitoring and measurement capabilities needed to provide robust data to characterize material deposition, detect build anomalies, and provide feedback control; and also a limited proper understanding of post-build processing that can effectively and reproducibly control materials properties to enable part qualification and certification. Because of the rapid layer-by-layer fabrication of AM, these measurement science challenges usually encompass several orders of magnitude in the spatiotemporal domain and require us to search deep into our materials characterization arsenal and invent new characterization techniques as required. Neutrons, because they are uncharged and only interact with atomic nuclei via the strong force, possess an even greater capability to penetrate metallic materials than high-energy xrays and enable measurements of voids, phases, and residual stresses in large, industry-relevant AM parts. Because of these unique capabilities, many stateof-the-art x-ray and neutron characterization techniques have been applied to understand the processing, structure, and properties of AM metals. [...]Capek et al.6 presented a very interesting study on Inconel 718 under uniaxial tensile