β-sialon/alumina/silica mixtures were sintered in flowing nitrogen at 1500℃ and 1600℃ respectively. The sintering properties and morphology of samples were investigated by SEM, EDS and XRD. Results show that sinter...β-sialon/alumina/silica mixtures were sintered in flowing nitrogen at 1500℃ and 1600℃ respectively. The sintering properties and morphology of samples were investigated by SEM, EDS and XRD. Results show that sintered properties of the samples are influenced by soaking temperatures and compositions. Bulk densities of samples are increased with the increase of the soaking temperature, whereas the apparent porosities are decreased. Mass loss of the sintered samples at 1500℃ is lower than that at 1600℃, but all the mass loss remains approximately constant with the increase of sialon content. From the point of thermodynamic analysis, Complex chemical reactions take place in samples during sintering process and the volatile of SiO (g) is responsible for the mass loss of samples. Compared to cross section microstructure of β-sialon/Al_ 2O_ 3/SiO_ 2 mixtures sintered in coke powder bed consisting of the dense center with well-developed column of sialon phase, the transitional part with needle like grain nitrogen-containing phase and the loose part with short granular Al_2O_3 phase, those of mixtures sintered in flowing nitrogen is made of well-developed sialon in dense center and slightly loose part with sialon debris.展开更多
文摘β-sialon/alumina/silica mixtures were sintered in flowing nitrogen at 1500℃ and 1600℃ respectively. The sintering properties and morphology of samples were investigated by SEM, EDS and XRD. Results show that sintered properties of the samples are influenced by soaking temperatures and compositions. Bulk densities of samples are increased with the increase of the soaking temperature, whereas the apparent porosities are decreased. Mass loss of the sintered samples at 1500℃ is lower than that at 1600℃, but all the mass loss remains approximately constant with the increase of sialon content. From the point of thermodynamic analysis, Complex chemical reactions take place in samples during sintering process and the volatile of SiO (g) is responsible for the mass loss of samples. Compared to cross section microstructure of β-sialon/Al_ 2O_ 3/SiO_ 2 mixtures sintered in coke powder bed consisting of the dense center with well-developed column of sialon phase, the transitional part with needle like grain nitrogen-containing phase and the loose part with short granular Al_2O_3 phase, those of mixtures sintered in flowing nitrogen is made of well-developed sialon in dense center and slightly loose part with sialon debris.
