Rethinking 3D Printing for ceramics

Ceramic additive manufacturing has long been viewed as a frontier full of promise yet plagued by technical barriers. While laser-based powder bed fusion (PBF-LB) has become a mature technology for metals, extending its capabilities to ceramics remains a challenge due to the materials’ low thermal conductivity, high melting points, and tendency to crack under thermal stress. In a recent study, researchers from ETH Zurich (ETHZ) and the Paul Scherrer Institute (PSI) have made a significant breakthrough in understanding how ceramics behave during PBF-LB, offering new tools and insights that could unlock broader industrial use.

Combining advanced numerical modeling with real-time experimental observations, the team focused on aluminum oxide (alumina), a widely used engineering ceramic. At ETHZ, they developed a high-fidelity computational framework capable of simulating the complex thermo-fluid behavior within the melt pool, including surface tension effects and phase transitions. These simulations revealed that, unlike metals, alumina forms shallow and wide melt pools due to its high laser absorptivity and limited ability to conduct heat away from the laser interaction zone. Marangoni-driven surface flows dominate, distributing energy laterally rather than deeply into the material.

To verify these insights, PSI carried out operando synchrotron tomographic microscopy at the TOMCAT beamline—capturing the melt pool’s 3D evolution during printing with unprecedented detail. The experimental data validated the simulation results, not only confirming melt pool geometry but also supporting the proposed flow mechanisms.

Beyond characterizing melt behavior, the study produced the first virtual process map for PBF-LB of alumina, predicting stable combinations of laser power and scanning speed that avoid defects such as balling or cracking. This map provides a powerful tool for process optimization, reducing trial-and-error experimentation in ceramic 3D printing.

By integrating in-situ imaging with high-resolution simulation, this ETHZ-PSI collaboration marks a major step toward predictive, defect-free ceramic additive manufacturing. Their work lays the foundation for wider application of PBF-LB in technical ceramics, from aerospace to biomedical engineering—bringing the field closer to the robust, industrial-grade processes already established for metals.