| Summary: | 碩士 === 國立中興大學 === 材料工程學研究所 === 89 === TiO2 bulks were joined by means of ceramic transient-liquid-phase bonding method with Bi2O3 powder interlayer in this study. The bonding interface was investigated microstructurally by scanning electron microscopy (SEM), chemically by electron probe microanalysis (EPMA), and mechanically by four-point bending test. Fracture surfaces were observed by means of SEM and phases at interfaces were identified by X-ray diffraction.
Three interface compounds 2Bi2O3-3TiO2, Bi2O3-4TiO2 and Bi2O3-2TiO2 were found at the interfaces under various conditions. In low temperature, the 2Bi2O3-3TiO2 formed at TiO2 / Bi2O3 interface. With time increases Bi2O3-4TiO2 appeared at TiO2 / 2Bi2O3-3TiO2 interface. When temperature increases Bi2O3-4TiO2 and Bi2O3-2TiO2 were found, and 2Bi2O3-3TiO2 was replaced. The growth form of 2Bi2O3-3TiO2 is grain growth and that of Bi2O3-2TiO2 is like coral growth. The average bonding strength reaches the maximum value of 16.4MPa in this study under the bonding condition of 900℃ and 6 hours. The activation energy of growth of 2Bi2O3-3TiO2 and Bi2O3-4TiO2 are 50 kJ/mole and 98 kJ/mole, respectively.
|
|---|
