Microstructure and Mechanical Properties of Alumina/Creium Oxide composites

• Main Authors: Chen, Sheau-Wen, 陳筱文
• Other Authors: Chii-Shyang Hwang
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/41580363089272212548

碩士 === 國立成功大學 === 材料科學(工程)學系 === 84 === The microstructure affects the properties of ceramics . In this study , Al2O3 and CeO2 were selected as the matrix and additive , respectively . The effect of atmosphere on microstructure, mechanical properties and annealing of Al2O3/ CeO2 composites was investigated . Results indicated that the Al2O3/CeO2 composites sintered at 1600℃/20min in air contained two phases ofα-Al2O3 and CeO2. However , the phases were α-Al2O3 and CeAl11O18 (β-alumina ) that sintered in N2+5%H2 atmosphere ; The equiaxed CeO2 grain was about 0.4 .mu.m and the length and aspect ratio of CeAl11O18 with elongated grain were 7.5 .mu.m and 7 , respectively . The bending stress and fracture toughness of the specimens sintered at 1600℃in N2+5%H2 were 579 MPa and 5.2 MPa．m1/2, respectively. The major faors influence the mechanical properties were residual stress, fracture mold, elongated grain distribution and relative density for Al2O3/CeO2 composites. After annealing in air, the CeAl11O18 contained in the samples sintered in N2+5%H2 decomposed to Al2O3and CeO2. The rate of decomposition showed a sudden increase at 1300℃and reacted completely at 1500℃for 1h.