Aluminum Nitride Shaping By Non-aqueous Gelcasting And Ceramic Materials Preparing By Simulating 3D Printing Technology

Aluminum nitride（AlN） ceramics has been prepared by a modified non-aqueous gelcasting technique, and the ceramic slurries with low viscosity and high solid loading were obtained by using 1-methyl-2-pyrrolidinone as solvent and Solsperse 24000 as dispersant. The rheological behaviors of the AlN ceramic slurry and the densities of AlN ceramics were studied. Typically, the AlN ceramic slurry（Solsperse 24000 of 0.5 wt% and solid loading of 50 vol%） showed a viscosity of 0.09 Pa·s at shear rate of 100 s-1. And more interestingly, increasing solid loading to 55 vol%, the AlN slurry still kept a low viscosity of about 0.28 Pa·s. As a result, the resultant green body exhibited a relative density of 65.5%, and a flexural strength of 42.3 MPa. After sintering at 1900 °C for 5 h, the AlN ceramics with an improved relative density of 99.4% was produced. Thus, this research would provide a new way to prepare low-viscosity and high solid-loading AlN slurry.Gelcasting ceramic slurry and 3D printing technology were combined together as experimental ideas and new curing system was selected to prepare thermoplastic slurry, which contained solid paraffin, bees wax, polyethylene wax, EVA wax as thermoplastic material and the volume ratio of 10:5:3:2, Solsperse 17000 as dispersant. Typically, the alumina（Al₂O₃） ceramics slurry of 3D printing technology with solid loading of 58 vol% was prepared. The debinding system of Al₂O₃ green body was developed reasonably according curing system TG curve analysis. In addition, the microstructures of green body and sintered body were characterized by electron scanning electron microscopy（SEM）, and the phase analysis of Al₂O₃ sintered body was characterized by X-ray diffraction（XRD）.