| Title |
Manufacture and Properties of {β}-SIC-TiB_2 Composites Densified by Pressureless Annealing |
| Authors |
신용덕(Shin, Yong-Deok) ; 주진영(Ju, Jin-Young) ; 박미림(Park, Mi-Lim) |
| Keywords |
Electroconductive ceramic composites ; Pressureless-annealed ; YAG ; PTCR |
| Abstract |
The effect of Al_2O_3+Y_2O_3 additives on fracture toughness of {β}-SiC-TiB_2 composites by hot-pressed sintering was investigated. The {β}-SiC-TiB_2 ceramic composites were hot-press sintered and pressureless-annealed by adding 16, 20, 24 wt% {β}-SiC-TiB_2(6:4 wt%) powder as a liquid forming additives at low temperature(1800 °C) for 4 h. Phase analysis of composites by XRD revealed mostly of {α}-SiC(6H), TiB_2, and YAG(Al_5Y_3O_{12}). The relative density was over 95-88 % of the theoretical density, and the porosity increased with increasing Al_2O_3+Y_2O_3 contents because of the increasing tendency of pore formation. The fracture toughness showed the highest value of 5.88 MPa·m^{1/2} for composites added with 20 wt% Al_2O_3+Y_2O_3 additives at room temperature. The electrical resistivity showed the lowest value of 5.22×10^{-4} {Ω} · cm for composite added with 20 wt% Al_2O_3+Y_2O_3 additives at room temperature, and was all positive temperature coefficeint resistance(PTCR) against temperature up to 900 °C |