Application of polypropylene carbonate for the tape casting of silicon nitride ceramics

Abstract QPAC40 (polypropylene carbonate), with a little decomposition residue, is commonly used as a binder in aluminum nitride (AlN) tape casting. In this paper, we tried to explore its application in silicon nitride (Si ₃ N ₄ ) tape casting. By studying the influence of dispersant, binder, plasticizer/binder ratio, and solid loading on slurry and green tape properties, the optimum formulation of the tape casting of Si ₃ N ₄ slurry was determined, and the green tape with a uniform structure and relative density up to 63.16% was prepared. Si ₃ N ₄ ceramics were obtained by debinding at 600°C for 1 h in vacuum and gas‐pressure sintering at 1830°C for 2 h in N ₂ . The thermal conductivity and flexural strength of Si ₃ N ₄ ceramics were 56.28 ± 1.21 W/(m·K) and 1130.67 ± 23.58 MPa, respectively. These results indicated that QPAC40 can be used to prepare Si ₃ N ₄ sheets through tape casting.