Gelating and Drying Process of Aqueous Gelcasting Aluminum Nitride Ceramics.

In this study, aluminum nitride ( AlN) ceramics were first prepared by aqueous gelcasting. The effect of various parameters such as concentration of N, N-dimethylacrylamide ( DMAA, as monomers), N, N′-methylenbisacrylamide ( MBAM, as cross-linking agent), ammonium persulfate amount ( APS, as initiator), solid content and polymerization temperature on AlN ceramics was discussed for aqueous gelcasting system. Finally, drying methods of aqueous gelcasting AlN green bodies were investigated. Aqueous gelcasting AlN ceramics, sintered at 1850°C for 4 h, had homogeneous grain size and little grain boundary phase, and the relative density, flexural strength and thermal conductivity of aqueous gelcasting AlN ceramics were 99.9%, 333(±10) MPa, 136(±9) W/(m·K), respectively. [ABSTRACT FROM AUTHOR]