| About this Abstract |
| Meeting |
MS&T21: Materials Science & Technology
|
| Symposium
|
Engineering Ceramics: Microstructure-Property-Performance Relations and Applications
|
| Presentation Title |
Mechanical, Thermal, and Electrical Properties of Pressureless Sintered SiC Ceramics with BN and C Additives |
| Author(s) |
Young-Wook Kim, Rohit Malik |
| On-Site Speaker (Planned) |
Young-Wook Kim |
| Abstract Scope |
The full densification of SiC ceramics with 0.5–2.7 wt% BN and C addition has been achieved by pressureless sintering route. The electrical resistivity decreased by an order of magnitude (10<sup>6</sup> → 10<sup>7</sup> Ω·cm) as BN content increased from ~0.5 to ~0.9 wt% because of the increased BN-derived B doping in the SiC lattice. A further increase in BN content had no significant effect on the electrical resistivity, which is attributed to the limited solubility of B in the SiC lattice. The thermal conductivity decreased with increasing BN content owing to increased phonon scattering at B-doped sites and the thermally insulating BN phase located at the grain boundaries. The fracture toughness was found to increase with increasing BN content owing to crack bridging caused by the BN platelets. However, intrinsically weak BN grains with low hardness were responsible for reduced flexural strength and hardness with increasing BN content. |