YU Liang, LIU Yuan, LIU Guoqing, JIANG Yanli
(College of Materials Science and Engineering, Guilin University of Technology, Guilin 541004, Guangxi, China)
Abstract: With SAD as raw material, Al2O3 ceramic skeleton with grid structure [Al2O3(3D)] was prepared by using 3D printing/gel casting (3D/DC) technology. Microstructure, phase composition and internal structure of the Al2O3(3D) were studied by means of SEM, XRD, XPS and CT. It was found that the diffraction peak intensities of MgAl2O4 and NaAl11O17 decreased with increasing sintering temperature from 1250 ℃ to 1450 ℃. Optimum sintering temperature of the grid structure ceramics is 1450 ℃ and the sintering time is 4 h. In the sintering process, Si in the Si-O-Si bond of the Al2O3(3D) was replaced by Al to form Si-O-Al bond. When the content of kaolin was increased from 0 wt.% to 15 wt.%, the maximum load of ceramics increased from 1.8 kN to 12.2 kN. As the content of kaolin reached 20 wt.%, the failure mode of the ceramics changed from piecewise failure to brittle fracture of foam ceramics. When the kaolin content was increased from 0 wt.% to 20 wt.%, the cracks with different shapes in the ceramics gradually disappeared and large circular holes remained.
Key words: aluminum dross; ceramics; sintering process; sintering mechanism