A Study on the Mechanical Properties of RBSC/Graphite Composites

,; ,; ,; ,; ,; ,; ,; ,

J. Korean Ceram. Soc. > Volume 35(6); 1998 > Article

Journal of the Korean Ceramic Society 1998;35(6): 626.

RBSC/Graphite 복합재료의 기계적 특성에 관한 연구

서기식, 박상환, 하조웅¹, 정윤중²

한국과학기술연구원 복합기능 세라믹스 연구센터
¹동양시멘트 중앙연구소 신소재연구실
²명지대학교 공과대학 무기재료공학과

A Study on the Mechanical Properties of RBSC/Graphite Composites

ABSTRACT

RBSC(Reaction Bonded Silicon Carbide) / graphite composites were fabricated by the method of melt Si in-filtration using a continuous reaction sintering process in SiC/graphite preforms. The SiC grain and residual graphite particle size in RBSC/graphite composites were increased with increased graphite particle size used in SiC/graphite preforms. The fracture strength of RBSC/graphite composites was 345-450 MPa. The frac-ture strength was reduced as increasing of the graphite size because of the formation of large abnormal SiC grains and residual graphites in RBSC/graphite composites. The fracture toughness of RBSC/graphite com-posites using graphite particle of 25$mutextrm{m}$ was 5.5 MP{{{{ {am }^{1/2 } }} The increased fracture toughness of RBSC/gra-phite composites seems to be due to the increasing in crack deflection by pull-out of residual graphites and integranular fracture of fine SiC grains around residual graphites

Key words: Reaction bonded silicon carbide, RBSC/graphite composite, Infiltration