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Electron beam melting (EBM) is a metal powder bed fusion additive manufacturing (AM) technology that is used to fabricate three-dimensional near-net-shaped parts directly from computer models. Ti-6Al-4V is the most widely used and studied alloy for this technology and is the focus of this work in its ELI (Extra Low Interstitial) variation. Microstructure evolution and its influence on the mechanical properties of the alloy in the as-fabricated condition have been documented by various researchers. In the present work, different heat treatments were performed based on three approaches in order to study the effects of heat treatments on the unique microstructure formed during the EBM fabrication process. In the first approach, the effect of various cooling rates after the solutionizing process was studied. In the second approach, a correlation between the variation of α lath thickness during aging and the subsequent effect on mechanical properties was established. Lastly, several combined solutionizing and aging experiments were conducted; the results will be systematically discussed in the context of structural performance and design.

Electron Beam Melting (EBM) is a metal powder bed fusion Additive Manufacturing (AM) technology that makes possible the fabrication of three-dimensional near-net-shaped parts directly from computer models. EBM technology has been continuously evolving, optimizing the properties and the microstructure of the as-fabricated alloys. Ti-6Al-4V ELI (Extra Low Interstitials) titanium alloy is the most widely used and studied alloy for this technology and is the focus of this work. Several research works have been completed to study the mechanisms of microstructure formation, evolution, and its subsequent influence on mechanical properties of the alloy. However, the relationship is not completely understood, and more systematic research work is necessary in order to attain a better understanding of these features. In this work, samples fabricated at different locations, orientations, and distances from the build platform have been characterized, studying the relationship of these variables with the resulting material intrinsic characteristics and properties (surface topography, microstructure, porosity, micro-hardness and static mechanical properties). This study has revealed that porosity is the main factor controlling mechanical properties relative to the other studied variables. Therefore, in future process development, decreasing the porosity should be considered the primary goal in order to improve mechanical properties.

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Additive manufacturing (AM) refers to an advanced technology used for the fabrication of three-dimensional near-net-shaped functional components directly from computer models, using unit materials. The fundamentals and working principle of AM offer several advantages, including near-net-shape capabilities, superior design and geometrical flexibility, innovative multimaterial fabrication, reduced tooling and fixturing, shorter cycle time for design and manufacturing, instant local production at a global scale, and material, energy, and cost efficiency. Well suiting the requests of modern manufacturing climate, AM is viewed as the new industrial revolution, making its way into a continuously increasing number of industries, such as aerospace, defense, automotive, medical, architecture, art, jewelry, and food. This overview was created to relate the historical evolution of the AM technology to its state-of-the-art developments and emerging applications. Generic thoughts on the microstructural characteristics, properties, and performance of AM-fabricated materials will also be discussed, primarily related to metallic materials. This write-up will introduce the general reader to specifics of the AM field vis-à-vis advantages and common techniques, materials and properties, current applications, and future opportunities.