2026 ASEE Annual Conference & Exposition

This research investigates the integration of Material Extrusion (MEX) polymer patterns into metal casting using a process inspired by Lost Foam Casting (LFC). In this approach, the MEX polymer pattern is not removed prior to pouring; instead, it thermally degrades and disintegrates upon contact with molten metal during the casting process. This approach enables the fabrication of complex geometries without the need for dedicated pattern tooling, which is traditionally required in conventional casting methods. The study aims to evaluate the influence of key process parameters on both the additive manufacturing stage and the casting stage. On the MEX side, parameters such as material selection and printing conditions are critical to ensure that the polymer pattern achieves controlled thermal disintegration during metal pouring. Among various MEX materials, Polylactic Acid (PLA) was selected due to its relatively lower emission of harmful by-products during thermal degradation compared to many other thermoplastics. Additionally, a lightweight variant of PLA (LW-PLA) was used, which can reduce the material density by up to approximately 40%, making it suitable for low-volume pattern applications. Following the casting process, the produced aluminum components were evaluated based on dimensional accuracy and surface quality to determine the feasibility of the Lost Polymer Casting (LPC) process. Furthermore, the study clarifies the relationship between additive manufacturing parameters and the resulting dimensional accuracy and surface finish of aluminum castings. These findings contribute to the development of a knowledge base for optimizing LPC processes and demonstrate the potential of additive manufacturing in advancing modern metal casting technologies.