Additive manufacturing (AM), also known globally as three-dimensional (3D) printing, has been gaining traction, since it allows the use of digital models to directly produce components by depositing the required materials one layer at a time. In contrast to conventional subtractive manufacturing processes, the greatest advantage of AM lies in the significant reduction of material waste, while simultaneously enabling much more complex structures, whose topology optimisation may be easily performed, with a wide range of geometric forms. Owing to these outstanding characteristics, AM is now an essential technology in high-value industrial fields, such as aerospace and aeronautics, where performance, weight reduction, and design flexibility are key requirements. Particularly, metal additive manufacturing (MAM) has been growing significantly, with powder bed fusion (PBF) currently being the most widely used process, followed by directed energy deposition (DED) and material extrusion, although the latter is still mostly applied to polymers. The wide range of industrial applications of these technologies includes aircraft ducts, brackets and housings, structurally optimised components, in addition to the repair and manufacture of high-value parts, such as turbine blades and rotor shafts. This review offers a descriptive and updated overview of the state-of-the-art of additive manufacturing technologies applied to the aerospace and aeronautics sectors. It analyses current applications, materials used, and process paths, while critically discussing the key technological and regulatory challenges that continue to limit broader industrial adoption, especially in terms of quality assurance, process repeatability, certification, and compliance with the tight industry standards. Furthermore, emerging trends and future research directions are outlined, providing a forward-looking perspective on this technology’s role in shaping next-generation aerospace components. By consolidating dispersed knowledge and synthesising recent scientific and industrial advances, this article’s objective is to serve as a foundational reference for both established researchers and newcomers to the field, supporting informed research, technology development, and industrial decision-making in metal additive manufacturing for aerospace applications.




