Stereolithography Additive Manufacturing of Conductive SiOC‐Cu Interpenetrating Phase Composite with Improved Ductility, Thermal Stability, and Corrosion Resistance

Abstract Cermets are important for engineering applications due to their unique combination of strength, hardness, and corrosion resistance. Current manufacturing methods cannot shape cermets into complex designs easily, while additive manufacturing techniques tend to introduce porosity and incur substantial costs related to equipment and post‐processing. To circumvent these limitations, cost‐effective stereolithography 3D printing of Cu powder mixed with preceramic photoresist is employed. Upon pyrolysis at 1000 °C, a cermet with interpenetrating phases of Cu and SiOC (SiOC‐Cu) is formed. The SiOC‐Cu cermet exhibits a high ceramic content of 51.3 vol% with relatively low porosity (≈5%), as well as electrical (4.926 × 10 5 S m −1 ) and thermal conductivity (9.2990 W/mK) similar to Mn, but at only 70% of its density (≈5.0 g cm −3 ). The 3D‐printed SiOC‐Cu cermet is able to maintain dimensional stability up to 1200 °C and resist nitric acid attack for >2 h due to the presence of the inert SiOC network. The continuous Cu phase, on the other hand, improves the strength and compressive energy absorption of SiOC by 2.9× and ≈25×, respectively. Most remarkably, the ductility of the cermet reaches > 80% in compression (no fracture strain) and 8.6% in tension, which far surpasses those of previous cermets.