Graduate student Matthew Mathesius will be defending his thesis titled “Rotating-Bending Fatigue Performance of Material Extruded Additively Manufactured Inconel 718.”

Matthew Mathesius thesis defense

• Date: Thursday, April 23
• Time: 3-4 p.m.
• Location: IST 1003
• Current major: M.S. student of mechanical engineering
• Thesis committee chair: Dr. Sanna F. Siddiqui
• Committee members: Dr. Edwar Romero-Ramirez and Dr. Navindra Wijeyeratne

Abstract

Additive manufacturing has become a developing manufacturing process in recent decades due to the ability to produce components of complex geometries difficult to obtain through traditional manufacturing processes. Many notable more common metal additive manufacturing processes exist, including Laser-Powder Bed Fusion (L-PBF), Direct Energy Deposition (DED), and Binder Jetting Printing (BJP). These processes each have unique benefits, but due to varying concerns such as high equipment acquisition and maintenance costs, safety concerns when handling metal powders, and the intensive reporting on present microstructural defects that inhibit optimal fatigue performance, the widespread expansion of these processes proves difficult.

This work looks to address this concern through the investigation of the material extrusion additive manufacturing (MEAM) process, a low-cost additive manufacturing process using metal powder bound in polymeric filaments that are extruded layer-by-layer through a heated nozzle. Knowledge gaps exist in the fields of understanding fatigue performance of MEAM Inconel 718 (IN718) under rotating bending fatigue loading, alongside the effects of induced microstructural defects during the printing and post-processing stages of part development.

The novelty of the current study is that it has created a framework for optimal printing and debinding parameters for MEAM IN718 components. The rotating bending fatigue performance of as-built MEAM IN718 is further analyzed through different build orientations (i.e., horizontal and vertical) and flow rates using the optimized print parameter set discovered in the current study. Overall, this works serves as an initial standard to assess the viability of materially extruded IN718 for high-strength and fatigue aerospace applications.

Acknowledgments: This study is supported under the National Science Foundation (NSF) Career Grant No. (2338178), awarded to Dr. Sanna F. Siddiqui.

For more information, please contact Dr. Sanna Siddiqui.