Feasibility of Metal Additive Manufacturing for Internal Combustion Engines

Abstract

As the advancement of metal additive manufacturing (AM) technology persists, so will the expansion of its capabilities and applications. Therefore, automotive and defense industries will need to adapt to these changing trends to remain competitive and sustainable. One potential way of accomplishing this is through the implementation of AM into internal combustion (IC) engines. As a result, the work presented in this thesis aims to expand on this opportunity by demonstrating the process and feasibility of using AM to produce working IC engine components. Through efforts of reverse engineering, model modifications, parameter selection, build layout optimization, and support structure design, the production of a crankcase and cylinder head from a Saito FG-11 engine was made possible. CT scans were subsequently used to quantify whether defects such as cracks, geometric deviations, and porosity were present/ critical. Once viability of the parts was established, machining and other post-possessing was completed to create fully functional parts. To adequately test engine performance, an entirely new setup and strategy had to be designed and executed, first with a propeller and secondly with an existing dynamometer. Each engine was monitored at the same specific set points during operation for speed, torque, temperatures, pressures, airflow, and mass flow of fuel. The results proved that while the AM engine did have a degraded performance, it was operable and even ran without failure for over 3.5 hours during testing. The major influencers behind the degraded performance were hypothesized to be either variations in assembly, or increased frictions from an insufficient honing procedure. Moreover, there was not enough evidence against the AM process itself for it to be considered a cause, thus deeming this endeavor successful.