ABSTRACT
Additive manufacturing (AM) of high-resolution components for applications in the defense, aerospace, power generation, propulsion, and biomedical industries has led to accelerated design and production schedules of these parts as well as geometric flexibility, leading to the development of more complex component designs. AM technologies use a digital solid model (e.g., Computer-aided design, CAD) to develop a component layer-by-layer, with layer thickness varying depending upon the material used during manufacturing. Among the most commonly used AM processes are the powder-bed technologies, which include selective laser sintering (SLS), direct metal laser sintering (DMLS), electron beam melting (EBM), and selective laser melting (SLM), from which a variety of alloys such as Inconel 718 (IN718), Stainless Steel 316L and Ti-6Al-4V can be produced. The SLM process involves selectively melting metal powder by a high-energy laser within an inert gas (nitrogen or argon) environment. The focus of 226this review is on understanding the effect of SLM processing parameters on the microstructure and mechanical properties of Ni-based superalloys commonly used in the manufacturing of components subjected to elevated temperatures. The main goal here is to highlight the developments and to reflect on further research needed to better understand the SLM AM process. In addition to this review, this paper will present simulated elastoplastic tensile stress–strain response of SLM Inconel 718 and heat-treated SLM Inconel 718 exhibiting anisotropy, based upon mechanical properties found in literature. It will also discuss the viability of using the resulting tensile stress–strain response trends observed for SLM Inconel 718 and heat-treated SLM Inconel 718, to model a first-order approximation of the elastic behavior (e.g., Young’s Modulus) response with build orientation.
