Agglomeration-free nanosized ZrO2-HfO2-Y2O3-Sc2O3 composite powders were successfully synthesized by Sol-Gel technique in heated aqueous solution of alcohol, using analytically pure ZrOCl2 · 8H2O, HfOCl2·8H2...Agglomeration-free nanosized ZrO2-HfO2-Y2O3-Sc2O3 composite powders were successfully synthesized by Sol-Gel technique in heated aqueous solution of alcohol, using analytically pure ZrOCl2 · 8H2O, HfOCl2·8H2O, Y（NO3）3·6H2O, and Sc2O3 as raw materials. The effect of synthesis condition on the size and dispersity of the composite powders was investigated by means of XRD, TEM, and TG-DSC techniques. The results showed that well-dispersed predecessor of ZrO2-HfO2-Y2O3-Sc2O3 composite nanopowders could be obtained. The optional condition ： PEG6000 as dispersant was 1%, alcohol/H2O ratio was 5/1, metallic ion concentration in whole solution was 0.5 mol·L^-1 and the pH value of the solution was 12. After calcined at 620 ℃, the powder obtained was in uniform cubic structure, and its average particle size was about 13 nm, which was good for producing nanocrystalline solid electrolyte.展开更多
The rheological behavior and gelcasting of composite suspensions of SiC and synthesized Al 2O 3-Y 2O 3-La 2O 3 powder as sintering aid were investigated. It was found that the rheological behavior of SiC particles cou...The rheological behavior and gelcasting of composite suspensions of SiC and synthesized Al 2O 3-Y 2O 3-La 2O 3 powder as sintering aid were investigated. It was found that the rheological behavior of SiC particles could be modified with a slightly oxidized surface that was similar to silica in colloidal behavior. The smaller the particles were, the more similar to silica the SiC powder was. The pH value of Al 2O 3-Y 2O 3-La 2O 3 synthesized powder slurry at isoelectric points (IEP) is higher than that of SiC powder. The dispersant PAA-NH 4 changes the IEP of both SiC and Al 2O 3-Y 2O 3-La 2O 3 powder slurry to higher pH values. The experimental results indicate that the composite suspension could possess satisfactory stability and lower viscosity at pH =10.1 and PAA-NH 4 as dispersant. The optimum solid loading was 550 0 in volume. Machinable green bodies with uniform complex shape are gained after molding.展开更多
基金Project supported by the National Natural Science Foundation of China (20101006)Nano Technology Special Foundationof Shanghai Science and Technology Committee (0452nm073) and Shanghai Education Committee
文摘Agglomeration-free nanosized ZrO2-HfO2-Y2O3-Sc2O3 composite powders were successfully synthesized by Sol-Gel technique in heated aqueous solution of alcohol, using analytically pure ZrOCl2 · 8H2O, HfOCl2·8H2O, Y（NO3）3·6H2O, and Sc2O3 as raw materials. The effect of synthesis condition on the size and dispersity of the composite powders was investigated by means of XRD, TEM, and TG-DSC techniques. The results showed that well-dispersed predecessor of ZrO2-HfO2-Y2O3-Sc2O3 composite nanopowders could be obtained. The optional condition ： PEG6000 as dispersant was 1%, alcohol/H2O ratio was 5/1, metallic ion concentration in whole solution was 0.5 mol·L^-1 and the pH value of the solution was 12. After calcined at 620 ℃, the powder obtained was in uniform cubic structure, and its average particle size was about 13 nm, which was good for producing nanocrystalline solid electrolyte.
文摘The rheological behavior and gelcasting of composite suspensions of SiC and synthesized Al 2O 3-Y 2O 3-La 2O 3 powder as sintering aid were investigated. It was found that the rheological behavior of SiC particles could be modified with a slightly oxidized surface that was similar to silica in colloidal behavior. The smaller the particles were, the more similar to silica the SiC powder was. The pH value of Al 2O 3-Y 2O 3-La 2O 3 synthesized powder slurry at isoelectric points (IEP) is higher than that of SiC powder. The dispersant PAA-NH 4 changes the IEP of both SiC and Al 2O 3-Y 2O 3-La 2O 3 powder slurry to higher pH values. The experimental results indicate that the composite suspension could possess satisfactory stability and lower viscosity at pH =10.1 and PAA-NH 4 as dispersant. The optimum solid loading was 550 0 in volume. Machinable green bodies with uniform complex shape are gained after molding.
