Preparation of titanium nitride ultrafine powders by sol–gel and microwave carbothermal reduction nitridation methods

2009 ◽  
Vol 35 (3) ◽  
pp. 1071-1075 ◽  
Author(s):  
Haijun Zhang ◽  
Faliang Li ◽  
Quanli Jia
Keyword(s):  
Titanium Nitride ◽  
Carbothermal Reduction ◽  
Sol Gel ◽  
Ultrafine Powders

Oxidation Behavior of β-Sialon Ultrafine Powders Prepared by the Combined Sol-Gel and Microwave Carbothermal Reduction Nitridation Method

2018 ◽  
Vol 281 ◽  
pp. 34-39
Author(s):  
Fa Liang Li ◽  
Fang Fu ◽  
Li Lin Lu ◽  
Hai Jun Zhang ◽  
Shao Wei Zhang
Keyword(s):  
Activation Energy ◽  
Carbothermal Reduction ◽  
Oxidation Behavior ◽  
Oxidation Process ◽  
Sol Gel ◽  
Probable Mechanism ◽  
Ultrafine Powders ◽  
Isothermal Thermogravimetry ◽  
Temperature Range ◽  
Mechanism Function

Ultrafine powders of β-Sialon were prepared by the combined sol-gel and microwave carbothermal reduction nitridation method, and their oxidation process was studied by a non-isothermal thermogravimetry method. The results indicated that two different mechanism functions respectively corresponded to the initial and final oxidation stages. The reverse Jander equation with activation energy of 240.5 kJ/mol and the Avrami-Erofeev equation with activation energy of 410.7 kJ/mol were respectively identified as the most probable mechanism function for the initial and final oxidation stages in the temperature range of 1423-1623 K.

Effects of polyvinylpyrrolidone on carbothermal reduction and nitridation of titanium nitride powder

2015 ◽  
Vol 19 (sup9) ◽  
pp. S9-73-S9-76
Author(s):  
L. F. Zhang ◽  
J. L. Bu ◽  
H. Y. Wei ◽  
Y. Cui ◽  
H. X. Liu ◽  
...  
Keyword(s):  
Titanium Nitride ◽  
Carbothermal Reduction ◽  
Nitride Powder

Preparation of porous SiC ceramic with a woodlike microstructure by sol-gel and carbothermal reduction processing

2004 ◽  
Vol 24 (10-11) ◽  
pp. 3251-3259 ◽  
Author(s):  
Jun-Min Qian ◽  
Ji-Ping Wang ◽  
Guan-Jun Qiao ◽  
Zhi-Hao Jin
Keyword(s):  
Carbothermal Reduction ◽  
Sol Gel ◽  
Sic Ceramic ◽  
Porous Sic

scholarly journals Titanium Nitride Coating of Graphite Using the Sol-gel Method

TANSO ◽  
1991 ◽  
Vol 1991 (146) ◽  
pp. 15-21
Author(s):  
Kanichi Kamiya ◽  
Takayoshi Atsumi ◽  
Hiroyuki Nasu
Keyword(s):  
Titanium Nitride ◽  
Sol Gel ◽  
Nitride Coating ◽  
Gel Method ◽  
Sol Gel Method ◽  
Titanium Nitride Coating

Biomorphic SiC Prepared from Carbonized Millet by Sol-Gel and Carbothermal Reduction Processing

2010 ◽  
Vol 152-153 ◽  
pp. 1683-1686
Author(s):  
Qing Wang ◽  
Ya Hui Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Silicon Carbide ◽  
Phase Composition ◽  
Carbothermal Reduction ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbon Template ◽  
Scanning Electron

Biomorphic silicon carbide (bioSiC) was prepared by high temperature pyrolysis and sol-gel and carbothermal reduction processing at 1600 oC. The morphology and microstructure of carbon-silica composites and purified bioSiC samples were characterized by scanning electron microscopy. The phase composition of the resulting sample was analyzed by X-ray diffraction. The results suggest that the bioSiC mainly consists of cubic ß-SiC, and principally replicates the shape and microstructure of the carbon template.

Synthesis of Biomorphic Silicon Carbide from Wood

2008 ◽  
Vol 1094 ◽  
Author(s):  
Kwok Cheung Li ◽  
Dickon H. L. Ng
Keyword(s):  
Silicon Carbide ◽  
Carbothermal Reduction ◽  
Wood Sample ◽  
Sol Gel ◽  
Reduction Process ◽  
Delonix Regia ◽  
Specific Strength ◽  
Sic Ceramics ◽  
Gel Technique

AbstractWe have successfully produced biomorphic SiC ceramics from silica-infiltrated wood samples of balsa (Ochroma pyramidale) and flame tree (Delonix regia). This conversion of wood sample to a structure of SiC was performed by a sol-gel technique and a carbothermal reduction process. The biomorphic products were confirmed containing β-SiC and their structures were replica of the original structures of the raw wood samples. The biomorphic products from the denser flame tree (C-SiC) had higher specific strength than that from the biomorphic product from balsa (SiC).

Preparation of β–SiC Nanorods with and Without Amorphous SiO2 Wrapping Layers

1998 ◽  
Vol 13 (9) ◽  
pp. 2533-2538 ◽  
Author(s):  
G. W. Meng ◽  
L. D. Zhang ◽  
C. M. Mo ◽  
S. Y. Zhang ◽  
Y. Qin ◽  
...  
Keyword(s):  
Carbothermal Reduction ◽  
Carbon Nanoparticles ◽  
Sol Gel ◽  
Silica Xerogels ◽  
Amorphous Sio2

Preparation of β–SiC nanorods with and without amorphous SiO2 wrapping layers was achieved by carbothermal reduction of sol-gel derived silica xerogels containing carbon nanoparticles. The β–SiC nanorods with amorphous SiO2 wrapping layers were obtained by carboreduction at 1650 °C for 1.5 h, and at the end of 1.5 h the temperature was steeply raised to 1800 °C and held for 30 min; they are typically up to 20 µm in length. The diameters of the center thinner β–SiC nanorods within the amorphous SiO2 wrapping layers are in the range 10–30 nm, while the outer diameters of the corresponding amorphous SiO2 wrapping layers are between 20 and 70 nm. The β–SiC nanorods without amorphous SiO2 wrapping layers were produced by carbothermal reduction only at 1650 °C for 2.5 h, and their diameters are in agreement with those of the center thinner β–SiC nanorods wrapped in amorphous SiO2 layers. Large quantities of SiC rod nuclei and the nanometer-sized nucleus sites on carbon nanoparticles are both favorable to the formation of much thinner β–SiC nanorods. The formation of the outer amorphous SiO2 wrapping layer is from the combination reaction of decomposed SiO vapor and O2.

scholarly journals A novel sol–gel route to synthesize (Sr0.5Ba0.5)Nb2O6 ceramics with enhanced electrocaloric effect

2017 ◽  
Vol 07 (02) ◽  
pp. 1750012 ◽  
Author(s):  
Ting Chen ◽  
Shu Ya Wu ◽  
Xiao Qiang Liu ◽  
Xiang Ming Chen
Keyword(s):  
Sol Gel ◽  
Synthesis Temperature ◽  
Ultrafine Powders ◽  
X Ray Diffraction ◽  
Electrocaloric Effect ◽  
X Ray ◽  
Fine Powders ◽  
Sol Gel Process ◽  
Size And Morphology ◽  
Mechanism Of The Reaction

(Sr[Formula: see text]Ba[Formula: see text])Nb2O6 ultra-fine powders were synthesized by a novel sol–gel route, and the mechanism of the reaction was discussed. SrCO3, BaCO3, oxalate niobium and citric acid were used to initiate the sol–gel process, and ethylene glycol (EG) was added to further polymerize the cross-linking structure. The evolution of the (Sr[Formula: see text]Ba[Formula: see text])Nb2O6 phase, the reaction process and the microstructures were investigated by X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy, DSC-TG and scanning electron microscopy. The synthesis temperature of the (Sr[Formula: see text]Ba[Formula: see text])Nb2O6 powders reached as low as 1200[Formula: see text]C, and the size and morphology of the powders were controlled by temperature. By adjusting the calcination temperature, we obtained (Sr[Formula: see text]Ba[Formula: see text])Nb2O6 powders with uniform sizes of 20[Formula: see text]nm to 500[Formula: see text]nm. Then, dense (Sr[Formula: see text]Ba[Formula: see text])Nb2O6 ceramics were successfully prepared using these ultrafine powders. Finally, an enhanced electrocaloric effect (ECE) value of 0.35[Formula: see text]C was obtained at 100[Formula: see text]kV/cm.

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