Direct Coagulation Casting of Silicon Carbide Components

Si, Wenjie; Graule, Thomas; Baader, F.H.; Gauckler, Ludwig J.

doi:10.1111/j.1151-2916.1999.tb01886.x

Cited by 83 publications

(55 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Aluminum hydroxide [Al(OH) 3 , 99.99%, 2.5¯m, Kojundo Chemical Lab. Co., Japan], boron oxide (B 2 O 3 , 99.9%, 3¯m, Kojundo Chemical Lab.…”

Section: Methodsmentioning

confidence: 99%

“…The present investigation reports the synthesis of Al 3 BC 3 powder using the mixtures of Al(OH) 3 , B 2 O 3 , and phenolic resin through carbo-thermal reduction process. Al(OH) 3 was selected in order to reduce the price and to increase the activity of the raw powder.…”

Section: )4)mentioning

confidence: 99%

“…Al(OH) 3 was selected in order to reduce the price and to increase the activity of the raw powder. Phenolic resin induced homogeneous distribution of carbon source because of the high solubility in ethanol.…”

Section: )4)mentioning

confidence: 99%

See 2 more Smart Citations

Synthesis of Al3BC3 particulates by carbo-thermal reduction process—Parameter optimization and mechanism analysis

Lee

Yin

et al. 2014

J. Ceram. Soc. Japan

View full text Add to dashboard Cite

The synthesis mechanism of Al 3 BC 3 through carbo-thermal reduction process was investigated and the processing conditions were optimized using Al(OH) 3 B 2 O 3 C as starting materials. The mass change and phase formation of the compacts were analyzed with varying temperature. Excess Al(OH) 3 and B 2 O 3 were required compared to the stoichiometric composition due to the loss of the source materials by vaporization at 1,5001,600°C. At 1,600°C, Al 2 O gas began to actively react with carbon to form Al 4 C 3 on the carbon particles. Al, Al 2 O and B 2 O 3 gases diffused through Al 4 C 3 layer and reacted with carbon at and above 1,650°C to form Al 3 BC 3 . The formation of hexagonal terrace at the surface of synthesized powder indicated that the gases also reacted at the particle surface with carbon which diffused through the carbide layers. The reactions were completed after calcination at 1,725°C for 4 h or at 1,800°C for 1 h. Gas-solid reactions were the major synthesis mechanism. The optimum composition for the synthesis of the ternary compound was Al(OH) 3 :B 2 O 3 :carbon = 0.7:1.4:0.25 by weight.

show abstract

“…Aluminum hydroxide [Al(OH) 3 , 99.99%, 2.5¯m, Kojundo Chemical Lab. Co., Japan], boron oxide (B 2 O 3 , 99.9%, 3¯m, Kojundo Chemical Lab.…”

Section: Methodsmentioning

confidence: 99%

Section: )4)mentioning

confidence: 99%

See 1 more Smart Citation

Synthesis of Al3BC3 particulates by carbo-thermal reduction process—Parameter optimization and mechanism analysis

Lee

Yin

et al. 2014

J. Ceram. Soc. Japan

View full text Add to dashboard Cite

show abstract

“…A small number of researchers have used ammonia or sodium hydroxide solutions to adjust the pH of their suspensions [6,7,8], whilst Si et al [9] used tetramethylammonium hydroxide (TMAH). In both cases the aim was to maximise the zeta potential of the SiC particles in aqueous suspension.…”

Section: Introductionmentioning

confidence: 99%

“…Due to the wide use of alumina ceramics, the dispersion of these powders into water has been extensively studied and the dispersants used are commonly polyelectrolytes such as polyacrylic acid (PAA), polymethylacrylic acid (PMAA) and their (usually ammonium) salts [1,2,3,4,5]. However, there are very few reported papers on the dispersion of silicon carbide, SiC, powders into water.A small number of researchers have used ammonia or sodium hydroxide solutions to adjust the pH of their suspensions [6,7,8], whilst Si et al [9] used tetramethylammonium hydroxide (TMAH). In both cases the aim was to maximise the zeta potential of the SiC particles in aqueous suspension.…”

mentioning

confidence: 99%

Effect of dispersants on the rheology of aqueous silicon carbide suspensions

Zhang

Binner

2008

Ceramics International

View full text Add to dashboard Cite

• This is a journal article. AbstractThe effect of cationic and anionic dispersants on aqueous suspensions of as-received and surface-modified silicon carbide particles has been studied via observation of the rheological behaviour. Only the cationic dispersants were effective for the as-received SiC, with polyethyleneimine being superior to Hyamine 2389 probably as a result of a greater electrosteric interaction. SiC particles modified using Al(NO 3 ) 3 behaved like alumina and so could be dispersed using the anionic dispersants ammonium polyacrylate and polymethacrylate. Such dispersions displayed no heteroaggregation when alumina was added, although the order of mixing could significantly affect the rheological behavior of the suspension. Nevertheless, the suspensions appeared robust to slight fluctuations in pH. I IntroductionAchieving adequate dispersion of ceramic powders is important for suspension-based ceramic green forming; it is generally necessary to prepare the suspensions with as high solid content and low viscosity as possible. Due to the wide use of alumina ceramics, the dispersion of these powders into water has been extensively studied and the dispersants used are commonly polyelectrolytes such as polyacrylic acid (PAA), polymethylacrylic acid (PMAA) and their (usually ammonium) salts [1,2,3,4,5]. However, there are very few reported papers on the dispersion of silicon carbide, SiC, powders into water.A small number of researchers have used ammonia or sodium hydroxide solutions to adjust the pH of their suspensions [6,7,8], whilst Si et al. [9] used tetramethylammonium hydroxide (TMAH). In both cases the aim was to maximise the zeta potential of the SiC particles in aqueous suspension. In contrast, Sano [10] used styrene-maleic acid copolymers, the resulting 33 vol% solid content suspension exhibited a viscosity of only 190 mPa s at a shear rate of 6.9 s -1 , whilst other promising dispersants are the weak cationic polyelectrolytes polyethyleneimine (PEI) and polyvinylimidazole (PVI). The former has been used for the flocculation of silica § , SiO 2 , suspensions [11] whilst the latter, which has similar properties to § The surface charge behaviour of SiO 2 and SiC is fundamentally similar because there is always a very thin layer of SiO 2 on the surface of SiC [12,13,14]. In both cases, therefore, the zeta potential is negative when the pH is higher than the point of zero charge (PZC), typically pH 3±1. The polyelectrolytes adsorb onto the surface of the particles due to the electrostatic attraction force between the particles and the ionised groups on the polymer segments, the level of adsorption also being dependent on the molecular weight of the polymer. 3PEI and shows good adsorption onto the surfaces of the particles, has been studied for dispersing SiC powder [15]. However, in neither case was a rheological study of the resulting suspensions reported.A further complicating factor when producing SiC ceramics is that sintering additives are usually required to generate liquid phases and h...

show abstract