• Title/Summary/Keyword: 연마

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Bending Strength Properties of SiC Ceramics at Different Roughness Values of Polishing Plates (연마판의 거칠기에 따르는 SiC 세라믹스의 굽힘강도 특성)

  • Nam, Ki-Woo;Kim, Eun-Sun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.7
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    • pp.779-784
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    • 2011

  • This study was carried out on the crack healing of three types of SiC ceramics based on a $SiO_2$ additive, taking into account the roughness of the polishing plate used for polishing the specimens. The mixtures were subsequently hot-pressed in $N_2$ gas for one hour under 35 MPa at 2053 K. In these specimens, the optimized crack-healing condition was 1373 K for one hour in air. The crack-healing material of the cracked part was the glassy phase of $SiO_2$ that was formed by the oxidation of SiC. In the optimum healing condition, the bending strength of non-polished SiC ceramics was not completely recovered. However, the bending strength of the SAY specimen was excellent, considering the economic aspects of SAY, SAYS-1, and SAYS-2. The SAY specimen is definitely superior to the others after an hour of heat treatment. There was a decrease in the number and size of defects in the specimen polished by using a $125-{\mu}m$ polishing plate; however, the micro-surface defects were not completely repaired. The specimen polished by using a 40-${\mu}m$ polishing plate showed little voids or surface defects after an hour of heat treatment. The bending strength of the specimen mirror-polished by using a 6-${\mu}m$ polishing plate was completely recovered.

  • https://doi.org/10.3795/KSME-A.2011.35.7.779 인용 PDF KSCI