부분소결공정에 의한 다공질 탄화규소 세라믹스의 제조 및 특성 |
김신한, 김영욱1, 윤중열2, 김해두3 |
서울시립대학교 산업기술연구소 1서울시립대학교 신소재공학 2한국기계연구원 세라믹재료그 3한국기계연구원 세라믹재료그룹 |
Fabrication of Porous SiC Ceramics by Partial Sintering and their Properties |
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ABSTRACT |
Addition of large particles restrains densification by small particles in mixed particle systems. In the present study, large SiC whiskers or particles were introduced into small particles for restraining densification and the mixtures were sintered using yttrium aluminum garnet (Y$_3$A1$sub$5/O$sub$12/, YAG) as a sintering additive. By controlling the content of large SiC whiskers or particles and the applied pressure during sintering, porous SiC ceramics, with a porosity ranging from 0.3% to 39%, were fabricated. Porosity increased with increasing the content of restraining materials. SiC whiskers were more effective than large SiC partcles for restraining densification. Permeability of the porous SiC ceramics increased with increasing the porosity. Flexural strength decreased with increasing porosity. A noticeable increase in strain to failure was observed in the porous ceramics with a porosity ranging from 18% to 39%. |
Key words:
Porous ceramics, SiC, Flexural strength, Strain-tolerant behavior |
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