Electrically and thermally conductive SiC ceramics

Abstract

Electrically and thermally conductive SiC ceramics were fabricated by hot-pressing ¢-SiC, 2 or 4 vol % TiN, and 2 vol % Y 2 O 3 powder mixtures in a nitrogen atmosphere. X-ray diffraction data indicated that the specimens consisted mostly of ¢-SiC grains and traces of ¡-SiC and Ti 2 CN clusters. Highly-conductive Ti 2 CN clusters segregated between SiC grains contributed to reduce the electrical resistivity of the TiN-doped SiC specimens. The high thermal conductivity of the TiN-doped SiC specimens was attributed to the lack of solubility of Ti and Y in the SiC lattice and the suppression of a massive ¢¼¡ phase transformation in SiC. The electrical resistivity and thermal conductivity of the SiC with 2 vol % TiN specimen were 2.4 © 10 ¹3 ³·cm and 174.1 W/m·K, respectively.

Mechanical and Thermal Properties of Pressureless Sintered Silicon Carbide Ceramics with Alumina–Yttria–Calcia

“…So far, most previous researches on pressureless, liquid‐phase sintering of SiC ceramics (LPS‐SiC) has focused on the Al 2 O 3 – Y 2 O 3 additive system, although a variety of other additive compositions have been investigated for sintering SiC using applied pressure. The additive compositions investigated for hot‐pressed, spark plasma sintered, or gas‐pressure sintered SiC ceramics include AlN, Al 2 O 3 –RE 2 O 3 (RE = La, Nd, Y, and Yb), AlN–RE 2 O 3 (RE = Sc, Lu, Yb, Er, and Y), Y 2 O 3 – RE 2 O 3 (RE = Sc, La, and Nd), Y 2 O 3 ‐nitrides, Al 2 O 3 – Y 2 O 3 – AlN, and RE‐nitrate (RE = Sc, Lu, Dy, Tb, Gd, Eu, Sm, Nd, Ce, and La) …”

Effects of Y2O3–RE2O3 (RE = Sm, Gd, Lu) Additives on Electrical and Thermal Properties of Silicon Carbide Ceramics

“…Research on the electrical or thermal properties of SiC ceramics has been conducted over the last three decades in order to further improve and/or control both the electrical and thermal conductivities of SiC ceramics. The electrical conductivity of polycrystalline SiC ceramics is strongly dependent on additive composition and sintering atmosphere . The electrical conductivities of SiC ceramics sintered in an argon atmosphere are as follows: 5.0 × 10 −3 (Ω·m) −1 for SiC ceramics sintered with 1 wt% B; 2 × 10 −2 –1.3 × 10 2 (Ω·m) −1 for SiC ceramics sintered with 1 wt% Al; 3.3 × 10 −12 (Ω·m) −1 for SiC ceramics sintered with 1 wt% Be; 1.0 × 10 −9 (Ω·m) −1 for SiC ceramics sintered with 10 wt% Al 2 O 3 –Y 2 O 3 ; 1.0 × 10 0 –7.7 × 10 −9 (Ω·m) −1 for SiC ceramics sintered with 3 vol% AlN–Y 3 Al 5 O 12 ; 2.8 × 10 −10 (Ω·m) −1 for SiC ceramics sintered with 7 wt% Al 2 O 3 –Er 2 O 3 ; 5.6 × 10 −7 (Ω·m) −1 for SiC ceramics sintered with 7 wt% Y 2 O 3 –Al 2 O 3 –CaO; 9.1 × 10 −4 (Ω·m) −1 for SiC ceramics sintered with 10 wt% Al 2 O 3 –Y 2 O 3 –AlN …”

Effects of the cross-sectional area ratios and contact resistance on the performance of a cascaded thermoelectric generator

“…In cold stage, material Bi 0.5 Sb 1.5 Te 3 is used. Moreover, in the two cases, in order to permit the heat transfer but insulate the current flow between the two stages and that from the outside of the cascaded thermoelectric generator, SiC is selected as the insulator to be applied on the top of the hot stage, on the bottom of the cold stage, and between the two stages, respectively.…”

“…In addition, the properties of copper as the electrode are shown in Table , and the insulator used in the current study has the following properties: …”