Mechanical and Electrical Properties of Hot-Pressed Silicon Carbide-Titanium Carbide Composites

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J. Korean Ceram. Soc. > Volume 32(10); 1995 > Article

Journal of the Korean Ceramic Society 1995;32(10): 1194.

고온가압소결한 SiC-TiC 복합체의 기계적, 전기적 특성

박용갑

선문대학교 공과대학 재료공학과

Mechanical and Electrical Properties of Hot-Pressed Silicon Carbide-Titanium Carbide Composites

ABSTRACT

The influences of TiC additions to the α-SiC on microstructural, mechanical, and electrical properties were investigated. Electrical discharge machinability of SiC-TiC composites was also studied. Samples were prepared by adding 30, 45, 60 wt.% TiC particles as a second phase to a SiC matrix. Sintering of SiC-TiC composites was done by hot pressing under a vacuum atmospehre from 1000 to 2000℃ with a pressure of 32 MPa and held for 90 minutes at 2000℃. Samples obtained by hot pressing were fully dense with the relative densities over 99% except 60wt.% TiC samples. Flexural strength and fracture toughness of the samples were increased with the TiC content. In case of SiC samples containing 45 wt.% TiC, the fracture toughness showed 90% increase compared to that of monolithic SiC sample. The crack propagation and crack deflection were observed with a SEM for etched samples after Vicker's indentation. The electrical resistivities of SiC-TiC composites were measured utilizing the four-point probe. The electrical dischage machining of composites was also conducted to evaluate the machinability.

Key words: SiC-TiC composite, Flexural strength, Fracture toughness, Crack deflection, Electrical resistivity, Electrical discharge machining