Part Quality Prediction Tools for Fused Deposition Processing

Fused Deposition process fabricates requested part geometries by sequentially depositing discrete curvilinear beads ofmaterial next to and on top of each other. The part integrity depends strongly on the bonding quality at the bead interfaces. Since diffusion bonding of thermoplastic components in the material system is thermally driven, temperature history ofinterfaces determine the bonding quality. Detailed thermal analysis of deposition region and layer building simulation for a model geometry have been performed to investigate local and global material behavior during processing. A simple transport property prediction model has also been developed for the determination of thermal transport properties of the particle loaded systems used in Fused Deposition. Based on the information obtained from thermal models, a computationally efficient part building model has been developed to predict bonding quality in the whole part. The model is driven by the same command file, sml file, that drives the Fused Deposition hardware; and hence is capable of replicating the building process. The model has been tested for a model geometry, spur gear, and three dimensional bonding quality distribution has been predicted for the part.