Effect of bentonite addition on fabrication of reticulated porous SiC ceramics for liquid metal infiltration

Soy, Ugur; Demir, Adem; Çalışkan, Fatih

doi:10.1016/j.ceramint.2010.07.028

Cited by 49 publications

(14 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Carbothermal synthesis of highly porous SiC ceramics with porosity of 82-84 % were prepared by means of polymeric technology and natural raw material at the temperature of 1400°C shows the compressive strength value in the range of 3.7-6.3 MPa [26]. Highly porous SiC foams were fabricated by polymeric sponge method with 10 % bentonite addition to the SiC particles gives foam maximum compressive strength of 2.44 MPa at 1100°C [27]. The commercial porous SiC (Duocel Ò ) used for gas diffusers, porous electrodes, rocket nozzle, core structures, flame arresters, high temperature filters, optics and mirrors possess the compressive strength of 1.38 MPa with a porosity 80-85 % (http://www.ergaerospace.com/Descriptors.htm).…”

Section: Resultsmentioning

confidence: 99%

Processing of silica bonded porous SiC preform for metallic composites

et al. 2015

View full text Add to dashboard Cite

Porous SiC ceramics were successfully fabricated by silica bonding of SiC compacts and porogen burnout technique. Silica coating on SiC particle was carried out using TEOS hydrolysis and crystallizes during the sintering process at 1200°C, which forms a well-developed neck growth between the SiC particles. Different volume fractions of sodium chloride porogen were used to obtain varied porosity content in porous SiC ceramics from 36 to 62.47 % leading to wide-ranging compressive strength from 8.11 to 0.69 MPa. Interconnected bimodal pores were created throughout the sample due to the burnt out of salt and stacking of SiC particles. The pore size distribution of porous SiC measured using mercury intrusion porosimetry shows that average pore size due to the salt particle is around 74-110 lm and stacking of SiC particle result 4-10 lm. Direct squeeze infiltration method is successfully adopted for infiltration of 6061 aluminium molten alloy into SiC preforms with the controlled process parameters of initial preform temperature, liquid metal superheating, squeezed pressure and its rate of application and die temperature. Microstructures have shown complete infiltration of Al alloy into the pores of the SiC preform forming Al composite with good interfacial bonding aided by the presence of MgAl 2 O 4 spinel. The silica coating on SiC surface have a multifunctional role of acting as a binder for the porous preform, enhances the wettability of SiC particle with molten metal during infiltration and prevention of deleterious Al 4 C 3 interfacial reaction product.

show abstract

Section: Resultsmentioning

confidence: 99%

Processing of silica bonded porous SiC preform for metallic composites

et al. 2015

View full text Add to dashboard Cite

show abstract

“…The maximum filter firing temperature is typically constrained to no more than 1200°C to minimize excessive oxidation and to ensure a longer furnace element or lining lifetime. Minimal SiC sintering is achieved at this temperature, and small amounts of fumed silica, clay, and other additives are added to improve strength . The filters are strong enough to be handled, but remain friable: small pieces break off of the filter edges during packaging and shipping and insertion into the filter housing at the foundry.…”

Section: Introductionmentioning

confidence: 99%

“…Minimal SiC sintering is achieved at this temperature, and small amounts of fumed silica, clay, and other additives are added to improve strength. [5][6][7][8][9] The filters are strong enough to be handled, but remain friable: small pieces break off of the filter edges during packaging and shipping and insertion into the filter housing at the foundry. If these pieces are entrained into the casting mold during molten metal pouring, they can produce surface defects in the molded part.…”

Section: Introductionmentioning

confidence: 99%

Ceramic Coatings and Glass Additives for Improved SiC‐Based Filters for Molten Iron Filtration

Tucker

2012

Int J Applied Ceramic Tech

View full text Add to dashboard Cite

Reticulated silicon carbide (SiC) ceramic filters are prepared with modified coatings in an attempt to improve mechanical properties of the sintered filter. Two classes of coatings are used: mixtures of non‐SiC ceramic and sintering aid and mixtures of SiC and glass. Various candidate ceramics, sintering aids, and glasses are screened. The most promising coatings are determined to be silica with 5 wt% bismuth oxide and SiC with ≤10 wt% Spruce Pine Batch glass. Filters with these coatings are prepared and subjected to mechanical abuse. Both coatings improve the ruggedness of the filter relative to the standard uncoated SiC type. Filters with <10 wt% glass additive were subjected to molten metal impingement and filtration of liquid gray iron at 1510°C. Those with 5 wt% glass or more softened during filtration. Those with 2.5 wt% glass or less survived without failure.

show abstract

“…One of the important natural minerals is the bentonite, which consists mainly of montmorillonite and contains varying amounts of other minerals like quartz and feldspar. The structure and swelling properties of Na-bentonite provide it with exceptional rheological properties that allow its dispersions to be widely used in different industrial applications, such as in drilling muds [1], [2], dyes, pharmaceuticals [3], paper, cement [4], nanocomposites [5], [6], polymer composites [7], thermal insulators [8] and ceramics [9].…”

Section: Introductionmentioning

confidence: 99%

The Modification of Rheological Properties of Bentonite-Water Dispersions with Cationic and Anionic Surfactants

Abu-Jdayil¹,

Ghannam²,

Nasser³

2016

IJCEA

View full text Add to dashboard Cite

Abstract-In the use of bentonite in different industrial applications, different additives are recommended to optimize the rheological properties of the formulation. In this study, the effect of anionic surfactant sodium dodecyl sulfate (SDS) and cationic surfactant cetyltrimethyl ammonium bromide (CTAB) on the rheological properties of Na-bentonite suspensions was investigated in the concentration range of . × − − . × − M. The SDS surfactant was effective in modifying the rheological behavior of bentonite dispersion in the concentration range that corresponds to critical micelle concentration (CMC) and critical coagulation concentrations (CCC) of SDS. On the other hand, the addition of CTAB surfactant to bentonite suspension reduced significantly its viscosity and shifted its behavior from shear thinning with a yield stress toward Newtonian.

show abstract

Effect of bentonite addition on fabrication of reticulated porous SiC ceramics for liquid metal infiltration

Cited by 49 publications

References 9 publications

Processing of silica bonded porous SiC preform for metallic composites

Processing of silica bonded porous SiC preform for metallic composites

Ceramic Coatings and Glass Additives for Improved SiC‐Based Filters for Molten Iron Filtration

The Modification of Rheological Properties of Bentonite-Water Dispersions with Cationic and Anionic Surfactants

Contact Info

Product

Resources

About