Additive Manufacturing of High and Ultra-High Temperature Ceramics and Composites: Processing, Characterization and Testing: Laser-based Additive Manufacturing, New Methods, and Testing
Sponsored by: ACerS Engineering Ceramics Division
Program Organizers: Corson Cramer, Oak Ridge National Laboratory; Greg Hilmas, Missouri University of Science and Technology; Lisa Rueschhoff, Air Force Research Laboratory
Tuesday 2:00 PM
October 19, 2021
Room: A111
Location: Greater Columbus Convention Center
Session Chair: Lisa Rueschhoff, Air Force Research Laboratory
2:00 PM Invited
Additive Slurry Drying as a Novel Method for Realizing Large Ceramic Components Using AM: Johannes Homa1; Yannik Zieger1; Martin Schwentenwein1; Shawn Allan2; 1Lithoz GmbH; 2Lithoz America LLC
AM of ceramic materials is steadily gaining interest and importance for a multitude of different applications. Two of the obstacles in this area are the comparably long post-processing times for debinding and sintering of printed green parts and the limitation to rather small geometries. To overcome these issues, this contribution will focus on a novel approach to structure water-based ceramic suspensions that allows printing and subsequent sintering of large and bulky components. By using a lithographic exposure process using a wavelength in the IR region the thermal energy that is generated is exploited to partially dry the suspensions and consolidate the green part with a high green density. For alumina, the resulting density and strength data is on the same level as for the respective conventional analogues. This process can also be used for highly light absorbing powder and hence, can be used as well for UHTCs.
2:40 PM
Additive Manufacturing of ZrB2–ZrSi2 Composites Using an Electron Beam Melting (EBM) Process: Cheryl Xu1; 1North Carolina State University
Owing to their high melting points and ability to resist extreme thermal stresses, ultra-high temperature ceramics (UHTCs) are important materials for critical applications, such as hypersonic flights, space re-entry vehicles, and rocket engines. Traditional manufacturing processes restrict the freedom to manufacture UHTCs with complex geometries due to the limitations of die and mold designs. Electron beam melting (EBM) is an established powder-bed layer-by-layer additive manufacturing (AM) process for metal parts. In this research, an effort has been made to EBM-process UHTC-based materials, and to investigate the microstructures of the fabricated materials under different processing conditions. For EBM fabrication of ZrB2- 30 vol% ZrSi2 composites, the optimal processing parameters has been simulated with a mathematical model. The results have been compared with experimental observations to valid the results and to obtain the optimized processing condition. This study demonstrates the capability for AM of UHTCs with complex geometries by the EBM technique.
3:00 PM
Process Development and Optimization for The Laser Powder Bed Fusion of WC-Ni Cermet Composites: Edgar Mendoza Jimenez1; Baby Reeja-Jayan1; Jack Beuth1; 1Carnegie Mellon University
In this work, laser powder bed fusion (LPBF) is used for the additive manufacturing of composite samples consisting of tungsten carbide particles with a nickel binder. Such process can become a viable low-energy alternative to the conventional production of ceramic-metal composites for applications including tooling, electronics, and wear components. Single track experiments are used to evaluate the melting behavior of the composite material. Three Dimensional samples are then printed with process parameters that adequately melted the material. The density, microstructure, chemical composition, and functional properties of these samples are characterized. Highly dense (>98%) samples were successfully manufactured and analyzed as a function of LPBF parameters. Macro and micro defects resulting from the laser processing are discussed and an optimal processing region is identified for the minimization of these defects.