Direct ink writing of polymer-derived SiBCN ceramics: Microstructure evolution, mechanical properties and thermal shock resistance

Additive manufacturing (AM) overcomes the processing challenges associated with the fabrication of complex ceramic geometries. Here, we proposed a direct ink writing (DIW) approach for PDC-SiBCN ceramics without introducing any additional organic additives, aiming to preserve the intrinsic properties of the ceramics. The effects of ink formulation and direct writing parameters on the forming performance of PDC-SiBCN ceramics were investigated. The optimized ink shows typical shear-thinning behavior, which can be used to fabricate complex structures, such as porous scaffolds, flexural bars, and honeycomb structures. Furthermore, the influence of pyrolysis temperatures on the microstructure and mechanical properties was analyzed. The ceramics achieved their maximum flexural strength and microhardness after pyrolysis at 1000 °C. The porous scaffolds maintained structural integrity without cracks or collapse after 200 thermal shock cycles, demonstrating good thermal shock resistance of the prepared PDC-SiBCN ceramics.