| 학회 |
한국재료학회 |
| 학술대회 |
2018년 가을 (11/07 ~ 11/09, 여수 디오션리조트) |
| 권호 |
24권 2호 |
| 발표분야 |
H. 한-일 재료공학(KJMST 2018) |
| 제목 |
Effect of Liquid Phase SiO2 on the Densification of Polycarbosilane-derived SiC Ceramics without Additives |
| 초록 |
Silicon carbide (SiC) is a very important for high temperature structural materials with excellent properties. SiC is one of the representative materials that has low sinterability. Due to the low sinterability as disadvantage, polymer precursor route and spark plasma sintering can be applied. Amorphous polycarbosilane powder that heat-treated at 1000°C was used to sintering. Using the SPS method, the PCS powder was sintered without additives at various sintering temperatures (1700, 1800, and 1900°C) and pressures (40 and 80 MPa). Both the applied sintering temperature and pressure had a strong influence on the densification of SiC. A SiC disc sintered at 1900°C under a pressure of 80 MPa showed an average relative density of 95%. In the SiC discs sintered at 1800 and 1900°C under a pressure of 80 MPa, the microstructure consisted of core, intermediate and rim regions: porous structure with only a β-SiC phase in the rim region; dense structure with α-SiC, graphite, and amorphous SiO2 in the core region; and a similar microstructure with a core region but denser in the intermediate region. The reduction and evaporation of SiO2 in the rim region inhibited densification and led to porous microstructure with large pores and grains. The presence of amorphous SiO2 in the core and intermediate regions induced the liquid phase sintering that has the higher sinterability and resulted in a higher densified microstructure with finer grains and pore sizes. The SiC grain rearrangement could occur easily by the presence of amorphous SiO2 induced from amorphous PCS at 1900°C and was facilitated by the applied pressure during SPS. |
| 저자 |
Ji Hwoan LEE1, Byung-Koog JANG2
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| 소속 |
1Interdisciplinary Graduate School of Engineering Sciences, 2Kyushu Univ. |
| 키워드 |
Polycarbosilane; silicon carbide; spark plasma sintering; Silicon dioxide; and densification
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| E-Mail |
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