Transmission Electron Microscopy Investigation of Hot-pressed ZrB2-SiC with B4C Additive |
Seongwon Kim, Jung-Min Chae, Sung-Min Lee, Yoon-Suk Oh, Hyung-Tae Kim, Byung-Koog Jang1 |
Engineering Ceramic Team, Korea Institute of Ceramic Engineering and Technology 1High Temperature Materials Unit, National Institute of Materials Science |
|
|
|
ABSTRACT |
This paper reports the microstructure of hot-pressed $ZrB_2$-SiC ceramics with added $B_4C$ as characterized by transmission electron microscopy. $ZrB_2$ has a melting point of $3245^{circ}C$, a relatively low density of $6.1g/cm^3$, and specific mechanical properties at an elevated temperature, making it a candidate for application to environments with ultra-high temperatures which exceed $2000^{circ}C$. Due to the non-sinterability of $ZrB_2$-based ceramics, research on sintering aids such as $B_4C$ or $MoSi_2$ has become prominent recently. From TEM investigations, an amorphous layer with contaminant oxide is observed in the vicinity of $B_4C$ grains remaining in hot-pressed $ZrB_2$-SiC ceramics with $B_4C$ as an additive. The effect of a $B_4C$ addition on the microstructure of this system is also discussed. |
Key words:
Ultra-high-temperature ceramics (UHTCs), $ZrB_2$-SiC, $B_4C$ addition, Densification |
|
|
|