Thermal Reactor Synthesis of Nanoscale Ceramic Powders using Organosilazane Aerosols

1991 ◽  
Vol 249 ◽  
Author(s):  
Tongsan D. Xiao ◽  
Peter R. Strutt ◽  
Kenneth E. Gonsalves ◽  
V. Shankar
Keyword(s):  
Particle Size ◽  
Cooling Rate ◽  
Thermal Conversion ◽  
Thermal Reactor ◽  
Ceramic Powders ◽  
Powder Synthesis ◽  
Critical Feature ◽  
Ceramic Particles ◽  
Sic Ceramic ◽  
Gas Cooling

ABSTRACTThis investigation involves the thermal conversion of an organosilazane precursors into ultrafine ceramic particles. In this process, aerosols of a reactive organosilazane precursor, [CH3SiHNH]n n = 3 or 4, are injected into a hot furnace to obtain Si3N4/SiC ceramic powders. One critical feature examined in this process was the rapidity of the powder synthesis, in a reaction which involves (i) elimination of ligand groups, (ii) formation of ceramic species, and (iii) condensation of ceramic species into ultrafine ceramic particles. Accompanying studies a model has been formulated to determine the gas cooling rate and particle size.

scholarly journals Effect of Particle Size Distribution on SiC Ceramic Sinterability

2017 ◽  
Vol 64 (6) ◽  
pp. 281-287 ◽  
Author(s):  
Nur Zalikha KHALIL ◽  
Sanjay Kumar VAJPAI ◽  
Mie OTA ◽  
Kei AMEYAMA
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Sic Ceramic ◽  
Effect Of Particle Size

Evaluations of cooling rate and initial temperature on thermal shock behavior of ZrB2-SiC ceramic

2018 ◽  
Vol 741 ◽  
pp. 509-513 ◽  
Author(s):  
Anzhe Wang ◽  
Ping Hu ◽  
Cheng Fang ◽  
Dongyang Zhang ◽  
Xinghong Zhang
Keyword(s):  
Thermal Shock ◽  
Cooling Rate ◽  
Initial Temperature ◽  
Sic Ceramic ◽  
Thermal Shock Behavior

Autocatalytic Ni-P and Ni-B Deposition on SiC Ceramic Particles

2015 ◽  
pp. 1493-1498
Author(s):  
Gökce Sezen ◽  
Ayfer Kilicarslan ◽  
Sibel Daglılar ◽  
Isıl Kerti
Keyword(s):  
Ceramic Particles ◽  
Sic Ceramic

scholarly journals Explosive Compaction of Si3N4, SiC Ceramic Powders and Whiskers.

1992 ◽  
Vol 39 (4) ◽  
pp. 266-271
Author(s):  
Hideshi Miura ◽  
Shinji Yoshihara ◽  
Tadatoshi Honda
Keyword(s):  
Ceramic Powders ◽  
Explosive Compaction ◽  
Sic Ceramic

Study of Heating and Cooling Rate of Cobalt Oxide-Based TCES System Using Experimental Redox Kinetics Analysis

2019 ◽  
Author(s):  
Nasser Vahedi ◽  
Carlos E. Romero ◽  
Mark A. Snyder ◽  
Alparslan Oztekin
Keyword(s):  
Particle Size ◽  
Energy Storage ◽  
Energy Density ◽  
Cooling Rate ◽  
Cobalt Oxide ◽  
Enthalpy Of Reaction ◽  
High Enthalpy ◽  
Pure Cobalt ◽  
Heating And Cooling ◽  
Redox Kinetics

Abstract Cost-effective solar power generation in CSP plants requires the challenging integration of high energy density and high-temperature thermal energy storage with the solar collection equipment and the power plant. Thermochemical energy storage (TCES) is currently a very good option for thermal energy storage, which can meet the industry requirement of large energy density and high storage temperature. TCES specifically exploits reversible chemical reactions wherein heat is absorbed during the forward endothermic reaction and released during the reverse exothermic reaction. The associated enthalpic storage of energy (i.e., the heat of reaction) offers higher density and enhanced stability compared to sensible and latent heat storage. Metal oxide redox reactions are particularly well-suited for TCES given their characteristically high enthalpy of reaction and high reaction temperature. In addition, the air is suitable as both a heat transfer fluid (HTF) and reactant; thus, simplifying process design and eliminating the need for indirect HTF storage and any intermediate heat exchanger. Among the palette of available metal oxides, cobalt oxide is one of the most promising candidates for TCES given its high enthalpy of reaction with high reaction temperature. One of the critical design parameters for TCES reactors is the optimal heating and cooling rates during respective charging and discharging modes of operation. In order to study the effect of heating/cooling rate on cobalt oxide TCES performance, a constant 10°C/min rate was selected for both storage cycle heating and cooling. Considering the intrinsic redox kinetics of cobalt oxide at considered constant heating/cooling rate, we studied milligram scale quantities of cobalt oxide (99.9% purity, 40 μm average particle size) using a dual-mode thermogravimetric (TGA)/differential scanning calorimetry (DSC) system, which simultaneously measures weight change (TGA) and differential heat flow (DSC) as a function of TCES cycling under continuous air purge. In addition, we investigated the cyclic stability of cobalt oxide in the context of the redox kinetics and particle coarsening behavior, employing scanning electron microscopy (SEM). TGA/DSC tests were conducted for 30 successive cycles using pure cobalt oxide. It was shown that pure cobalt oxide in powder form (38μ particle size) could complete both forward and reverse reaction at the selected heating rate with little degradation between cycles. In parallel, SEM was used to examine morphology and particle size changes before and after heating cycles. SEM results proved grain growth occurs even after only five initial cycles.

Fabrication of A356-based rolled composites reinforced by Ni–P-coated bimodal ceramic particles

2016 ◽  
Vol 232 (10) ◽  
pp. 803-815 ◽  
Author(s):  
R Kheirifard ◽  
N Beigi Khosroshahi ◽  
R Azari Khosroshahi ◽  
R Taherzadeh Mousavian ◽  
D Brabazon
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Average Particle Size ◽  
Microstructural Characterization ◽  
Rolling Process ◽  
Stir Casting ◽  
Ceramic Particle ◽  
Average Particle ◽  
Ceramic Particles ◽  
Sic Particles

Three arrangements of reinforced A356-based composites were fabricated. Samples with 3 wt% Al2O3 (average particle size: 170 µm), 3 wt% SiC (average particle size: 15 µm), and 3 wt% of mixed Al2O3–SiC powders (each reinforcement 1.5 wt%) were fabricated. The novel fabrication process of two-step stir casting followed by rolling was utilized. Analysis of the effect of using bimodal-sized ceramic particles and process parameters on the microstructure and mechanical properties of the composites was examined. Electroless deposition of nickel was used to improve the wettability of the ceramic reinforcements by the molten metal. From microstructural characterization, it was found that fine SiC particles were agglomerated, including when coated with Ni–P. It was also revealed that the rolling process broke the fine silicon platelets within the A356 matrix, which were mostly observed around the Al2O3 particles. The processed microstructure of the composite was altered in comparison to conventionally cast A356 MMC by translocation of the fractured silicon particles, by improving the distribution of fine SiC particles, and by elimination of porosities remaining after casting. A good bonding quality at matrix–ceramic interface was formed during casting and no significant improvement was found in this regard after the rolling process. The mechanical properties of the composites tested showed that the samples, which contained the bimodal ceramic particle distribution of coarse Al2O3 and fine SiC particles produced the highest levels of composite strength and hardness.

scholarly journals Effect of particle size and heating temperature of ceramic powders on antibacterial activity of their slurries.

1996 ◽  
Vol 29 (2) ◽  
pp. 251-256 ◽  
Author(s):  
Jun Sawai ◽  
Hideo Igarashi ◽  
Atsushi Hashimoto ◽  
Takao Kokugan ◽  
Masaru Shimizu
Keyword(s):  
Particle Size ◽  
Antibacterial Activity ◽  
Heating Temperature ◽  
Ceramic Powders ◽  
Effect Of Particle Size
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