Oxidation Resistance of Fully Dense ZrB2 with SiC, TaB2, and TaSi2 Additives |
| |
| Authors: | Fei Peng Robert F. Speyer |
| |
| Affiliation: | School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0245 |
| |
| Abstract: | Specimens of ZrB2 containing various concentrations of B4C, SiC, TaB2, and TaSi2 were pressureless-sintered and post-hot isostatic pressed to their theoretical densities. Oxidation resistances were studied by scanning thermogravimetry over the range 1150°–1550°C. SiC additions improved oxidation resistance over a broadening range of temperatures with increasing SiC content. Tantalum additions to ZrB2–B4C–SiC in the form of TaB2 and/or TaSi2 increased oxidation resistance over the entire evaluated spectrum of temperatures. TaSi2 proved to be a more effective additive than TaB2. Silicon-containing compositions formed a glassy surface layer, covering an interior oxide layer. This interior layer was less porous in tantalum-containing compositions. |
| |
| Keywords: | |
|
|
