WU Yanfang 1, 2, YU Jinhui 3, MEI Liling 4, MEI Hongling 4, YE Xiaoping 1, LI Yue 2, 5
(1. China Celadon College, Lishui University, Lishui 323000, Zhejiang, China; 2. School of Materials Science and Engineering, Zhejiang University, Hangzhou 310058, Zhejiang, China; 3. Longquan Museum, Longquan 323700, Zhejiang, China; 4. Zhejiang Tianfeng Ceramics Co.LTD, Longquan 323700, Zhejiang, China; 5. Research Institute of Zhejiang University-Wenzhou, Wenzhou 325006, Zhejiang, China)
Abstract: With the characteristics of high bulk density, high volume specific capacity, good fluidity and high sintering activity, alumina microspheres can be utilized for reinforcement and modification of ceramic materials. The effects of sintering temperature (1250-1370 ℃) on bending strength, linear shrinkage, water absorption and density of the alumina microsphere-modified Longquan celadon were studied, while the mechanism of the microstructural variation was proposed. Scanning electron microscopy (SEM), thermogravimetry- differential scanning calorimeter (TG-DSC), X-ray diffraction (XRD) and three-point bending test were employed to characterize microstructure, phase composition and bending strength of the samples. Microspherical corundum Al2O3 powder with an average size of 250 μm was achieved. With increasing sintering temperature, bending strength, linear shrinkage and density of the alumina microsphere-modified Longquan celadon samples were increased first and then decreased as the sintering temperature reached to 1370 ℃. The sample with 20% alumina microsphere after sintering at 1340 ℃ for 10 h showed optimal physical properties, with bending strength of 79.16 MPa, total shrinkage of 10.63%, water absorption was 0.064%, and density of 2.38 g×cm-3, which can be attributed to the formation and uniform distribution of long columnar crystalline grains in the celadon.
Key words: alumina microsphere; Longquan celadon; bending strength; water absorption; phase composition