Thermoelectric characteristics of the spark plasma-sintered silicon boride ceramics

방전 플라즈마 소결법으로 제조된 silicon boride 세라믹스의 열전 특성

  • 심승환 (한양대학교, 세라믹공정연구센터, 세라믹공학과) ;
  • 이대웅 (한양대학교, 세라믹공정연구센터, 세라믹공학과) ;
  • 채재홍 (요업기술원, 연구기획팀) ;
  • ;
  • 심광보 (한양대학교, 세라믹공정연구센터, 세라믹공학과)
  • Published : 2005.04.30

Abstract

Silicon boride ($SiB_6$) is very promising for use as thermoelectric materials at high temperature because of its high melting point and relatively large Seebeck coefficient. In the present work, spark plasma sintering (SPS) was applied for preparing dense $SiB_6$ ceramics, and their thermoelectric properties were investigated, together with their microstructural evaluation. The SPS process was found to be effective in densifying a $SiB_6$ ceramic, typically 99 % of the theoretical density at low temperature of $1500^{\circ}C$. In comparison with $SiB_6$ specimen prepared by hot-pressing, the SPS-processed specimen exhibited the significantly improved Seebeck coefficient, resulting in the higher power factor.

본 연구에서는 고온 융점과 높은 Seebeck 계수로 인해 고온 열전 재료로서 매우 우수한 silicon boride ($SiB_6$)의 고밀도 소결체를 방전 플라즈마 소결법(spark plasma sintering, SPS)을 도입하여 제조하였으며, 소결된 시편의 미세구조 및 열전 특성을 평가하였다. $1500^{\circ}C$의 비교적 저온에서 이론 밀도의 약 99%의 소결밀도로 SPS법을 통해 효과적으로 $SiB_6$를 치밀화 할 수 있었으며 이들 시편들의 열전특성 평가로부터, hot-press법으로 제조된 시편과 비교하여 매우 향상된 Seebeck 계수를 얻을 수 있었으며 상대적으로 높은 출력인자 값을 나타냈다.

Keywords

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