| Title |
Properties of the β-SiC-TiB_2 Composites with Al_2O_3+Y_2O_3 additives |
| Authors |
임승혁(Yim, Seung-Hyuk) ; 신용덕(Shin, Yong-Deok) ; 주진영(Ju, Jin-Young) ; 윤세원(Yoon, Se-Won) ; 송준태(Song, Joon-Tae) |
| Keywords |
Pressed and annealed β-SiC-TiB_2 ; Fracture Toughness ; PTCR |
| Abstract |
The mechanical and electrical properties of pressed and annealed β-SiC-TiB_2 electroconductive ceramic composites were investigated as a function of the liquid forming additives of Al_2O_3+Y_2O_3. Phase analysis of composites by XRD revealed α-SiC(6H), TiB2, and (Al5Y3O12). Reaction between Al2O3 and Y_2O_3 formed YAG but the relative density decreased with increasing Al_2O_3+Y_2O_3 contents. The Flexural strength showed the value of 458.9 MPa for composites added with 4 wt% Al_2O_3+Y_2O_3 additives at room temperatures. Owing to crack deflection and crack bridging, the fracture toughness showed 6.2, 6.0 and 6.6 MPa.m1/2 for composites added with 4, 8 and 12 wt% Al2O3+Y2O3 additives respectively at room temperature. The resistance temperature coefficient showed the value of 3.6×10^{-3}, 2.9×10^{-3} and 3.0×10^{-3} /°C°C for composite added with 4, 8 and 12 wt% Al_2O_3+Y_2O_3additives respectively at room temperature. The electrical resistivity of the composites was all positive temperature coefficient resistance(PTCR) in the temperature range of 25°C to 700°. |