Vat Photopolymerization of Cemented Carbide Specimen

Thomas Rieger, Tim Schubert, Julian Schurr, Andreas Kopp, Michael Schwenkel, Dirk Sellmer, Alexander Wolff, Juliane Meese-Marktscheffel, Timo Bernthaler, Gerhard Schneider
2021 Materials  
Numerous studies show that vat photopolymerization enables near-net-shape printing of ceramics and plastics with complex geometries. In this study, vat photopolymerization was investigated for cemented carbide specimens. Custom-developed photosensitive WC-12 Co (wt%) slurries were used for printing green bodies. The samples were examined for defects using quantitative microstructure analysis. A thermogravimetric analysis was performed to develop a debinding program for the green bodies. After
more » ... ntering, the microstructure and surface roughness were evaluated. As mechanical parameters, Vickers hardness and Palmqvist fracture toughness were considered. A linear shrinkage of 26–27% was determined. The remaining porosity fraction was 9.0%. No free graphite formation, and almost no η-phase formation occurred. WC grain growth was observed. 76% of the WC grains measured were in the suitable size range for metal cutting tool applications. A hardness of 1157 HV10 and a Palmqvist fracture toughness of 12 MPam was achieved. The achieved microstructure exhibits a high porosity fraction and local cracks. As a result, vat photopolymerization can become an alternative forming method for cemented carbide components if the amount of residual porosity and defects can be reduced.
doi:10.3390/ma14247631 pmid:34947227 pmcid:PMC8706196 fatcat:qyd4t76ebna5felkitn2zb5jvq