Date of Award
Master of Science in Engineering (MSE)
Sherri L. Messimer
D. Keith Hollingsworth
Three-dimensional printing., Manufacturing processes--Mathematical models.
Additive Manufacturing (AM) is a fabrication process that provides a cost effective alternative to conventional subtractive methods for small volume, complex parts. To accelerate development, numerical modeling methods are being evaluated to establish processing parameters thereby reducing the current trial and error methods. Resulting microstructure of an AM build is determined by the thermal profile it undergoes in-situ. This study uses a nominal approach to verify modeling predictions with metallurgical analysis of an as-built AM part. The finite difference additive thermal model (DATM) was used to construct temperature gradients from its generated temperature and time data simulated for a single bead plate build using 4340 steel. Predicted temperature gradients were overlaid onto time-temperature-transformation (TTT) and continuous cooling transformation (CCT) diagrams. Images from metallurgical evaluation of the actual build are compared with the predicted microstructures as a function of the cooling rate to verify results.
Stone, Jared, "Verifying predictive temperature gradients for an as-built additively manufactured part" (2020). Theses. 342.