| Title |
Effect of Pressurless Annealing Temperature on the Properties of α-SiC-WC Electroconductive Ceramic Composites. |
| Keywords |
{α}-SiC ; WC ; Liquid forming additives ; YAG ; Anneealing temperature ; PTCR |
| Abstract |
The composites were fabricated 61 vol.%α-α-SiC and 39vol.% WC powders with the liquid forming additives of 12wt% Al_2O_3＋Y_2O_3 by pressureless annealing at 1700, 1800, 1900°C for 4 hours. The result of phase analysis of composites by XRD revealed α-SiC(2H), WC, and YAG(Al_{5} Y_3O_{12} ) crystal phase. The relative density, the flexural strength, fracture toughness and Young's modulus showed respectively the highest value of 99.4%, 375.76㎫, 5.79㎫·m frac{1}{2}, and 106.43㎬ for composite by pressureless annealing temperature 1900°C at room temperature. The electrical resistivity showed the lowest value of 1.47×10^{-3} Ω.cm for composite by pressureless annealing temperature 1900°C at 25°C. The electrical resistivity of the α-SiC-WC composites was all positive temperature cofficient resistance (PTCR) in the temperature ranges from 25°C to 500°C. |