Enhancement of Mechanical Engineering Education With Additive Manufacturing Projects

Abstract

This paper presents an undergraduate research project developed to enhance mechanical engineering education at the University of Oklahoma. Selective Laser Sintering (SLS) is a promising additive manufacturing method for high-temperature materials with high spatial resolution and surface quality. As one of the most capable engineering-grade thermoplastics, polyether ketone (PEEK) can be used in additive manufacturing due to its elevated working temperature. This printer will use multiple heat zones, adjustable layer height, and a controlled hopper system to allow the user to fine-tune every print. In this paper, students are required to analyze the technical challenges of SLS based 3D printing technology. Using three separate controlled heat zones, the user will be able to hold the part above its glass transition temperature until the entire part finishes, therefore, annealing it in the process. This will additionally allow for testing and documentation of the effect of heat during preheating, pre-sintering, and post sintering. These features in a small-scale machine will allow thorough documentation of how controlled heated environments can alter the physical properties of a 3D printed part. Using a full steel platform with CNC machined parts and an off the shelf laser, the cost will be reduced to under ten thousand dollars. This undergraduate project to design an SLS based 3D printer provide a unique opportunity for students to fully understand the challenges of SLS manufacturing and gain experience in developing a complex 3D printing system.