Progress in Characterizing Curing and Debinding of Ceramic Inks for Stereolithography

ABSTRACT During ceramic stereolithography, laser photopolymerization must achieve high and uniform curing of monomers to ensure a crack‐free debinding step. In this study, we present a spatially resolved quantification of curing rate using Fourier transform infrared (FTIR) spectroscopy, relying on advanced deconvolution methods. Beyond the usual characterization performed on single‐layer samples, we quantify the curing rate on multilayer samples that are representative of real printed parts. Of particular interest is the pairing of FTIR spectroscopy with a numerical model calculating energy exposure from lasing parameters, enabling to confirm the presence of curing heterogeneities. For the first time in ceramic printing inks, we use low‐field nuclear magnetic resonance (LF‐NMR) relaxometry in addition to more usual chemical probes to assess curing rate based on the mobility of ink's organic species. The combination of dynamic mechanical analysis, also novel for this field, and differential scanning calorimetry, further reveals polymer network relaxation slightly below organic debinding temperature, which highlights the importance of a well‐controlled curing process. Finally, thermogravimetric analysis emphasizes favorable interactions between acrylate‐end groups and plasticizers, facilitating crack‐free gradual debinding at elevated temperature. These findings collectively provide valuable insights for optimizing ceramic stereolithography processes and improving part reliability.