Zirconia aqueous slurry was prepared with fine zirconia powder. Injection process for making zirconia fiber was demonstrated, including preparation of aqueous slurry, injection of slurry, fiber setting in acetone, and...Zirconia aqueous slurry was prepared with fine zirconia powder. Injection process for making zirconia fiber was demonstrated, including preparation of aqueous slurry, injection of slurry, fiber setting in acetone, and fiber firing. The principle of the process was discussed. The effects of solid loading in the zirconia slurry, addition of dispersant in the slurry, and ball milling time on the rheological properties of the slurry, especially yield stress, were illustrated. The role of acetone as curing agent was discussed. Zirconia poly-crystalline fiber with its density of 6. 05 g · cm^-3 was obtained after sintering at 1 530 ℃ for 5 h. Microstructure of the sintered zirconia fiber was investigated.展开更多
Viscose fiber templates(15 cm×15 cm×1 cm)were put into ZrOCl_(2) solutions of different concentrations(1,2 and 3 mol·L^(-1))and impregnated at different temperatures(20,40 and 60℃)for 20 h.After washin...Viscose fiber templates(15 cm×15 cm×1 cm)were put into ZrOCl_(2) solutions of different concentrations(1,2 and 3 mol·L^(-1))and impregnated at different temperatures(20,40 and 60℃)for 20 h.After washing,centrifugation and drying,ZrO_(2) fiber precursors were obtained.ZrO_(2) fibers were prepared by heat treatment of the precursors at different temperatures(600,800,1000 and 1200℃)for 2 h.The effects of the impregnation temperature,the impregnation solution concentration and the heat treatment temperature on the microstructure and the phase composition of the ZrO_(2) fibers were studied.The results show that with the increase of the impregnation temperature from 20℃to 60℃and the impregnation solution concentration increase from 1 mol·L^(-1) to 3 mol·L^(-1),the microstructure of fiber cross section changes from flat to cylindrical,and the average fiber diameter increases,indicating that the increase of the impregnation solution concentration and the impregnation temperature is beneficial to increasing the adsorption capacity of Zr4+on viscose fiber templates.After heat treatment,ZrO_(2) fiber mainly exists in the form of monoclinic ZrO_(2).With the increase of the heat treatment temperature,the grains in ZrO_(2) fibers become larger and the crystallinity degree increases,meanwhile the fiber surface undergoes a transition from smooth to small grains and then to cracks.展开更多
Polycrystalline 3Y-TZP/Al2O3 tetragonal zirconia fiber was obtained by the pyrolysis of gel fibers using zirconium oxychloride octahydrate（ZOC） as the raw material. The spinnable zirconia sol was prepared by electro...Polycrystalline 3Y-TZP/Al2O3 tetragonal zirconia fiber was obtained by the pyrolysis of gel fibers using zirconium oxychloride octahydrate（ZOC） as the raw material. The spinnable zirconia sol was prepared by electrolyzing the zirco-nium oxychloride octahydrate（ZOC） solution in the presence of acetic acid and sugar（ sucrose, glucrose or fructose） , in which the molar ratios of CH3 COOH/ZOC and sugar/ZOC were 1.0-4.0 and 0.2-0.4, respectively. The pre- pared tetragonal zireonia fibers sintered at different temperatures showed smooth and crack-free surfaces with diame, ters of 5-10 μm. The addition of Al2O3 enhanced the sintering process and prevented the crystals from growing. Thermogravimetric analysis（TG）, X-ray diffraction （ XRD ）, Fourier transform infrared spectroscopy（FTIR）, and scanning electron microscope（SEM） techniques were used to characterize the prepared fibers.展开更多
文摘Zirconia aqueous slurry was prepared with fine zirconia powder. Injection process for making zirconia fiber was demonstrated, including preparation of aqueous slurry, injection of slurry, fiber setting in acetone, and fiber firing. The principle of the process was discussed. The effects of solid loading in the zirconia slurry, addition of dispersant in the slurry, and ball milling time on the rheological properties of the slurry, especially yield stress, were illustrated. The role of acetone as curing agent was discussed. Zirconia poly-crystalline fiber with its density of 6. 05 g · cm^-3 was obtained after sintering at 1 530 ℃ for 5 h. Microstructure of the sintered zirconia fiber was investigated.
文摘Viscose fiber templates(15 cm×15 cm×1 cm)were put into ZrOCl_(2) solutions of different concentrations(1,2 and 3 mol·L^(-1))and impregnated at different temperatures(20,40 and 60℃)for 20 h.After washing,centrifugation and drying,ZrO_(2) fiber precursors were obtained.ZrO_(2) fibers were prepared by heat treatment of the precursors at different temperatures(600,800,1000 and 1200℃)for 2 h.The effects of the impregnation temperature,the impregnation solution concentration and the heat treatment temperature on the microstructure and the phase composition of the ZrO_(2) fibers were studied.The results show that with the increase of the impregnation temperature from 20℃to 60℃and the impregnation solution concentration increase from 1 mol·L^(-1) to 3 mol·L^(-1),the microstructure of fiber cross section changes from flat to cylindrical,and the average fiber diameter increases,indicating that the increase of the impregnation solution concentration and the impregnation temperature is beneficial to increasing the adsorption capacity of Zr4+on viscose fiber templates.After heat treatment,ZrO_(2) fiber mainly exists in the form of monoclinic ZrO_(2).With the increase of the heat treatment temperature,the grains in ZrO_(2) fibers become larger and the crystallinity degree increases,meanwhile the fiber surface undergoes a transition from smooth to small grains and then to cracks.
基金Supported by National High Technology Research and Development Program of China(No.2002AA2040).
文摘Polycrystalline 3Y-TZP/Al2O3 tetragonal zirconia fiber was obtained by the pyrolysis of gel fibers using zirconium oxychloride octahydrate（ZOC） as the raw material. The spinnable zirconia sol was prepared by electrolyzing the zirco-nium oxychloride octahydrate（ZOC） solution in the presence of acetic acid and sugar（ sucrose, glucrose or fructose） , in which the molar ratios of CH3 COOH/ZOC and sugar/ZOC were 1.0-4.0 and 0.2-0.4, respectively. The pre- pared tetragonal zireonia fibers sintered at different temperatures showed smooth and crack-free surfaces with diame, ters of 5-10 μm. The addition of Al2O3 enhanced the sintering process and prevented the crystals from growing. Thermogravimetric analysis（TG）, X-ray diffraction （ XRD ）, Fourier transform infrared spectroscopy（FTIR）, and scanning electron microscope（SEM） techniques were used to characterize the prepared fibers.
