Study on the microstructural and surface roughness variations of SLM IN718 overhangs
Abstract:
Inconel 718 (IN718), a nickel-based superalloy, is commonly used in nozzle turbines. Conventional manufacturing of complex IN718 geometries is difficult due to its high stiffness values. Consequently, additive manufacturing methods like selective laser melting (SLM), offer a viable solution for the fabrication of IN718 high accuracy. One of the limitations of this technique is its need of supports in order to fabricate overhanging structures. These supports need to be designed carefully and tend to consume resources. In this research, we study the angled structures fabricated without supports. The overhangs are fabricated using uniform process parameters for varying overhang angles and thicknesses. Microstructural and surface roughness analyses are carried out in order to determine variations in grain structure, melt pools and surface roughness. The outcome of this study will help us in predicting the need for supports in overhangs and inclined structures used within a part having complex geometry.