| About this Abstract |
| Meeting |
MS&T22: Materials Science & Technology
|
| Symposium
|
Engineering Ceramics: Microstructure-Property-Performance Relations and Applications
|
| Presentation Title |
Effect of Initial α-phase Content on Mechanical, Thermal, and Electrical Properties of Pressureless Sintered SiC Ceramics |
| Author(s) |
Young-Wook Kim, Shynar Kultayeva, Rohit Malik |
| On-Site Speaker (Planned) |
Young-Wook Kim |
| Abstract Scope |
By using α- and β-SiC starting powders, the effects of initial α-phase content on the properties of pressureless sintered SiC ceramics were investigated. For β-SiC starting powders, a coarse-grained microstructure with elongated platelet grains was formed by the β to α transformation of SiC in both solid state sintered (SSS) and liquid-phase sintered (LPS) SiC ceramics. In contrast, materials prepared from α-SiC powders exhibited a fine-grained microstructure with platelet grains in SSS-SiC and a fine-grained microstructure with equiaxed grains in LPS-SiC ceramics. This study revealed the beneficial effect of α-SiC starting powders in achieving low electrical resistivity and high thermal conductivity in SiC ceramics, which was attributable to their higher sinterability, lower impurity content, and lower phase transformation rate compared to β-SiC powders. The flexural strength increased by approximately 16% and 49% in SSS-SiC and LPS-SiC, respectively, with increasing initial α-phase content due to a decreased grain size. |