Fabrication of SiC ceramics with invariable value resistivity in the range of 20–400 ℃ using MAX phase- Ti3AlC2 additives

Abstract

SiC ceramics were fabricated by SPS sintering at 1850 ℃ with different amounts of Ti3AlC2. The effects of Ti3AlC2 content on the microstructure and electrical properties of the material were discussed. The densification and electrical properties of SiC ceramics have been improved by adding MAX phase Ti3AlC2. Ti3AlC2 decomposes to produce TiC and Al in the sintering process. The conductivity of SiC ceramics is elevated by TiC serving as a conductive second phase, and Al is dissolved into SiC lattice to promote the densification of SiC ceramics. With the addition of 15 wt% Ti3AlC2, the voltage-current curve of the sample changes from nonlinear to linear electrical characteristics with the resistivity dropping to 52 Ω cm. Moreover, the introduction of Ti3AlC2 reduces the temperature sensitivity of SiC ceramics. When the Ti3AlC2 content reaches 15 wt%, the resistivity of SiC ceramics remains relatively constant within the range of 20–400 ℃.