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- The mechanical and electrical properties of the hot-pressed and pressureless annealed SiC-TiB2 electroconductive ceramic composites were investigated as functions of the liquid additives of Al2O3+Y2O3. The result of phase analysis for the SiC-TiB2 composites by XRD revealed α-SiC(6H), TiB2, and YAG(Al5Y3O12) crystal phase. The relative density of SiC-TiB2 composites was increased with increased Al2O3+Y2O3 contents. The fracture toughness showed the highest value of 6.04 Mpaㆍm½ for composites added with 12wt% Al2O3+Y2O3 additives at room temperature. The electrical resistivity showed the lowest value of 6.2×10-3 Ωㆍ㎝ for composite added with 16wt% Al2O3+Y2O3 additives at room temperature. The electrical resistivity of the SiC-TiB2 composites was all positive temperature cofficient resistance(PTCR) in the temperature ranges from 25℃ to 700℃.