<scp>3D</scp> Printing Properties of Photo‐Sensitive Polysilazane Based Solvent‐Free Ceramic Slurry for Digital Light Processing

ABSTRACT Liquid polysilazane was applied as photo‐curable resin to formulate a solvent‐free ceramic slurry specifically tailored for Digital Light Processing (DLP) of Si‐C‐N non‐oxide ceramics. Following isocyanate ethyl acrylate (ICA) modification, polysilazane LSZ(3‐1‐3‐9) demonstrated optimal cure depth characteristics, while 2,4,6‐trimethylbenzoyl phosphate (TPO‐L) was identified as the ideal photo‐initiator. By implementation of a nano/μm ceramic powder blending strategy (incorporating 5% micron‐sized and 5% nano‐sized Si 3 N 4 particles), the bulk density of photo‐cured slurry was enhanced to 1.19 g/cm 3 and exhibited a penetration depth of 52.80 μm. Curing depth prediction model successfully quantifies the relationship between curing depth and critical exposure time. Incorporation of Si 3 N 4 powder facilitated accurate DLP printing, reduced mass loss and enhanced ceramic conversion in thermal pyrolysis. Progressive incorporation of Si 3 N 4 powder led to a gradual increase in bulk density and a corresponding reduction in porosity in the pyrolyzed ceramics. Scanning electron microscopy (SEM) analysis of the pyrolyzed ceramics revealed no observable agglomeration of Si 3 N 4 particles. Structural characterization indicated that ceramics sintered at 800°C maintained an amorphous structure, whereas those sintered at 1500°C exhibited enhanced crystallinity and uniform elemental distribution of Si, C, and N. This research provides an ideal solvent‐free polysilazane slurry for DLP processing of Si‐C‐N ceramic materials.