Torsional Fatigue Performance of Material Extruded Additively Manufactured Inconel 718

The nickel-based superalloy Inconel 718 (IN718) is commonly used in the aerospace industry in the fabrication of gas engine turbine blades, which undergo a combination of cyclic axial and torsional loadings coupled with extreme environments during service. Given the geometric complexity of these blades, additive manufacturing (AM), and more specifically, the material extrusion additive manufacturing (MEAM) process offers a potential cost-effective and easily accessible solution to these manufacturing challenges. The shortfall of this technique, however, is the potential risk of manufacturing defects introduced during part production, such as warping, surface texture, and shrinkage that could negatively impact the fatigue life and performance of these specimens. This study aims to investigate the torsional fatigue performance of MEAM IN718 as-built green parts of X- and Z-build orientation, and the role of processing parameters and manufacturing defects in the failure of these components, with on-going work exploring the role of debinding and sintering stages on performance. This knowledge can provide insight into the viability of MEAM for use within the aerospace industry.