Properties of the $\beta$-Sic+39vol.%$ZrB_2$ Composites Prepared by the Pressureless-Sintering

상압소결에 의해 제조한 $\beta$-Sic+39vol.%$ZrB_2$ 복합체의 특성

  • Shin, Yong-Deok (School of Electrical and Electronic Engineering, Wonkwang Univ.) ;
  • Ju, Jin-Young (School of Electrical and Electronic Engineering, Wonkwang Univ.) ;
  • Yoon, Se-Won (School of Electrical and Electronic Engineering, Wonkwang Univ.) ;
  • Hwang, Chul (School of Electrical and Electronic Engineering, Wonkwang Univ.) ;
  • Lim, Seung-Hyuk (School of Electrical and Computer Engineering, Sung Kyun Kwan Univ.) ;
  • Song, Joon-Tae (School of Electrical and Computer Engineering, Sung Kyun Kwan Univ.)
  • 신용덕 (원광대학교 공과대학 전기전자공학부) ;
  • 주진영 (원광대학교 공과대학 전기전자공학부) ;
  • 윤세원 (원광대학교 공과대학 전기전자공학부) ;
  • 황철 (원광대학교 공과대학 전기전자공학부) ;
  • 임승혁 (성균관대학교 공과대학 전기전자 및 컴퓨터공학부) ;
  • 송준태 (성균관대학교 공과대학 전기전자 및 컴퓨터공학부)
  • Published : 1999.11.20

Abstract

The $\beta$-SiC+$ZrB_2$ ceramic composites were pressureless-sintered and annealed by adding 4, 8, 12wt% $Al_{2}O_{3}+Y_{2}O_{3}$(6 : 4wt%) powder as a liquid forming additives at $1800^{\circ}C$ for 4h. The relative density is over 79.3% of the theoretical density and phase analysis of the composites by XRD revealed of $\alpha$-SiC(6H, 4H), $ZrB_2$, $Al_{5}Y_{2}O_{12}$ and $\beta$-SiC(15R). Flexural strength showed the highest of 301.33MPa for composites added with 8wt% $Al_{2}O_{3}+Y_{2}O_{3}$ additives at room temperature. Owing to crack deflection and crack bridging of fracture toughness mechanism, the fracture toughness showed the highest of $3.6979MPa{\cdot}m^{1/2}$ for composites added with 8wt% $Al_{2}O_{3}+Y_{2}O_{3}$ additives at room temperature. The electrical resistivity was measured by the Pauw method from $25^{\circ}C$ to $700^{\circ}C$. The electrical resistivity of the composites showed the PTCR(Positive Temperature Coefficient Resistivity).

Keywords