Gelcasting of aluminum nitride ceramics using hydantion epoxy resin as gelling agent

A gelling system based on the polymerization of Hydantion epoxy resin and 3,3′-Diaminodipropylamine (DPTA) was developed for gelcasting aluminum nitride (AlN) ceramics. The effect of the dispersant concentration and solid loading on the rheological behavior of the slurries was investigated. The highest solid loading of 58 vol% AlN ceramic slurry and the highest green relative density of 64.5% were obtained with the addition of 15 wt% Hydantion epoxy resin and 0.3 wt% dispersant Polyethyleneimine (PEI). With the addition of 20 wt% Hydantion epoxy resin, the flexural strength of AlN green body reached as high as 34.5 MPa. For sintered AlN ceramics, the relative density, flexural strength and thermal conductivity reached 99.6%, 360 MPa and 185 W/m K, respectively.