SiC-based ceramics with remarkable electrical conductivity prepared by ultrafast high-temperature sintering

SiC-based ceramics with high electrical conductivity are applied widely as electrode materials and semiconductor materials. In this study, a SiC-based ceramic with relative density of 96% was prepared by ultrafast high-temperature sintering (UHS) at 2000 ℃ (with a heating rate of 1000 ℃/min) for 40 s. The resistivity of as UHS-ed SiC-based ceramic was 1/15 of that prepared by the pressureless sintering. We found that the components of as-sintered body (SiC, Si and Y3Si5) by UHS were different from those (SiC and YAG) prepared by the pressureless sintering. The reason for the remarkable increase of the electrical conductivity of UHS-ed body was that the Si with higher electrical conductivity than SiC had emerged. Besides, the reaction mechanism was proposed and the unusual composition of the SiC-based ceramic sintered by UHS may also provide new reference for the application of SiC in specific fields.