Preparation and Sintering Characteristics of Ce0.8Gd0.2O1.9Powder by Ammonium Carbonate Co-precipitation

2012 ◽  
Vol 49 (1) ◽  
pp. 118-123 ◽  
Author(s):  
Young-Chang Yoo ◽  
Byung-Joo Chung ◽  
Soo-Man Sim
2007 ◽  
Vol 336-338 ◽  
pp. 2347-2349 ◽  
Author(s):  
Shang Yue Shen ◽  
Rui Yang ◽  
Qiang Shen ◽  
Chuan Bin Wang ◽  
Lian Meng Zhang

Al2(1-x)MgxTi1+xO5(x=0.05-0.3) composite powder was prepared by the method of chemical coprecipitation and subsequent sintering using TiCl4, MgCl2 and AlCl3 solution as the raw materials, and ammonia and ammonium carbonate as the solvent. Thermal dynamics and kinetic dynamics analysis of the precursor during the heat treatment were explored in detail, and the reaction process of Al2(1-x)MgxTi1+xO5 (x=0.3) composite powder was confirmed. Results show that, as the temperature increases MgO reacts with TiO2 of anatase phase to form MgTi2O5. At about 650°C, anatase transfers into rutile. Then MgTi2O5 reacts with Al2O3 to produce MgAl2O4 at 900°C. When the temperature is above 1100°C, the desired Al2(1-x)MgxTi1+xO5(x=0.3) composite powder is synthesized by the reaction of MgAl2O4, Al2O3 and TiO2 of rutile phase.


2011 ◽  
Vol 5 (4) ◽  
pp. 187-191 ◽  
Author(s):  
Radosław Lach ◽  
Krzysztof Haberko ◽  
Mirosław Bucko

Co-precipitation of alumina/YAG precursor from aluminum and yttrium nitrate solution with ammonium carbonate results in dawsonite. Its crystallographic parameters differ from the compound precipitated with no yttrium additive. It suggests that yttrium ions become incorporated into the dawsonite structure. The DSC/ TG and X-ray diffraction measurements show decomposition of dawsonite at elevated temperatures resulting in ?-Al2O3 and then ?- and ?-alumina modifications. Full transformation to ?-Al2O3 and YAG occurs at temperatures higher than 1230?C. Starting powder for the sintering experiments was prepared using the coprecipitated precursor calcined at 600?C. Seeding of such powder with 5 wt.% ?-Al2O3 results in material of 98% density at 1500?C. Much lower densification show compacts of unseeded powder.


2013 ◽  
Vol 788 ◽  
pp. 132-135 ◽  
Author(s):  
Yuan Jun Huang ◽  
Ting Liu ◽  
Min Liu

MgO-ZrO2nanosized powders have been synthesized via the co-precipitation route using ammonia, ammonium carbonate and ammonium hydrogen carbonate as precipitant, respectively. The three different powders were characterized by TG-DSC, XRD and SEM. And the sinterability behavior of each powder also has been investigated. The results indicated that uniformly dispersed and much looser MgO-ZrO2nanosized powders could be obtained when the ammonium carbonate, especially the ammonium hydrogen carbonate were used. When ammonia was used, some agglomeration could be observed. The crystalline grain size of the three powders is closed to each other. Due to the existing of agglomeration, the sintered samples prepared by using ammonia as precipitant exhibited poorer sinterability than that of using carbonates as precipitant.


2017 ◽  
Vol 8 (3) ◽  
pp. 2436-2447 ◽  
Author(s):  
Paul J. Smith ◽  
Simon A. Kondrat ◽  
Philip A. Chater ◽  
Benjamin R. Yeo ◽  
Greg M. Shaw ◽  
...  

Zincian georgeite, an amorphous copper–zinc hydroxycarbonate, has been prepared by co-precipitation using acetate salts and ammonium carbonate.


2003 ◽  
Vol 107 ◽  
pp. 945-948 ◽  
Author(s):  
P. M. Nicolaysen ◽  
E. Steinnes ◽  
T. E. Sjobakk

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