Flexural Strength of Macroporous Silicon Carbide Ceramics

Abstract

Macroporous silicon carbide (SiC) ceramics were fabricated by powder processing and polymer processing using carbon-filled polysiloxane as a precursor. The effects of the starting SiC polytype, template type, and template content on porosity and flexural strength of macroporous SiC ceramics were investigated. The β-SiC powder as a starting material or a filler led to higher porosity than α-SiC powder, owing to the impingement of growing α-SiC grains, which were transformed from β-SiC during sintering. Typical flexural strength of powder-processed macroporous SiC ceramics fabricated from α-SiC starting powder and polymer microbeads was 127 MPa at 29% porosity. In contrast, that of polymer-processed macroporous SiC ceramics fabricated from carbon-filled polysiloxane, β-SiC fillers, and hollow microspheres was 116 MPa at 29% porosity. The combination of α-SiC starting powder and a fairly large amount (10 wt%) of Al 2 O 3-Y 2 O 3 additives led to macroporous SiC ceramics with excellent flexural strength.

Processing and properties of macroporous silicon carbide ceramics: A review

“…Polymer precursors and artificial templates have also been used for producing porous SiC ceramics via sacrificial template method. Kim and his colleagues [45,[119][120][121][122][123][125][126][127][128] developed a new processing method for fabricating macroporous SiC ceramics from carbon-filled polysiloxane by carbothermal reduction and subsequent sintering process. The strategy adopted for making porous SiC ceramics involves the following: (i) fabricating a formed body from a mixture of polysiloxane, carbon source such as phenol resin or carbon black, SiC powder as an optional inert filler, sacrificial templates, and sintering additives; (ii) pyrolysis of polymeric materials; (iii) synthesizing SiC by carbothermal reduction; and (iv) sintering the materials.…”

Processing of Vermiculite-Silica Composites with Prefer-Oriented Rod-Like Pores

“…It is well documented that the mechanical strength of porous ceramics generally increases with decreasing porosity. [9][10][11] The VS2 sample showed the second highest strength (38 MPa in the direction parallel to the pressing direction and 68 MPa in the direction perpendicular to the pressing direction) among the samples investigated. The better strength of the VS2 was due to the lower porosity (48%) of the sample compared to that of the VS1 (54%) sample.…”

Effect of the C/Si Molar Ratio on the Characteristics of β-SiC Powders Synthesized from TEOS and Phenol Resin

“…서 론 탄화규소 (SiC)는 높은 열전도도와 내열성 및 내식성과 화학적 안정성이 우수하여 많은 산업분야에서 널리 사용 되고 있는 대표적인 비산화물계 세라믹스이다. [1][2][3][4] 최근에 β-SiC 세라믹스는 초집적 반도체 공정 및 LED 공정용 초 고순도 SiC 부품, 태양광 발전 및 고효율화를 위한 고품 위 SiC 에너지 반도체 등으로 쓰임이 확대되고 있다. SiC 세라믹스의 물성은 분말의 특성에 많은 영향을 받기 때 문에 원료 분말에 대한 관심이 증대되고 있다.…”