Abstract
ZrB2-SiC-Cr powder sintering at 1600 °C and its oxidation behavior at 1000–1500 °C in air were studied as a function of chromium content. It was shown that the relative density of the ZrB2-SiC ceramics increases with an increase in chromium content in the powdered mixture. This is related to the formation of the liquid Cr-Si-C-B phase during the high-temperature interaction of SiC with chromium and ZrB2. It was stated that the mechanism of ZrB2-SiC-Cr ceramics oxidation is changed from bulk to passive. The oxidation resistance is improved for the ceramics with 13% of chromium or less, which can be explained by a decrease in its porosity. The ceramics with higher chromium content demonstrates the opposite effect, namely, large-size Cr2O3 crystals are formed during oxidation, this promotes microcracking in the oxidizing layer and causes damage of surface integrity. As a result, the oxidation resistance of the ZrB2-SiC-Cr ceramics with high chromium content is decreased.
Original language | English |
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Article number | 105023 |
Number of pages | 8 |
Journal | International Journal of Refractory Metals and Hard Materials |
Volume | 84 |
DOIs | |
Publication status | Published - 1 Nov 2019 |
Keywords
- Borides
- Chromium
- Oxidation
- Silicon carbide
- Sintering
- Thermal properties
- DENSIFICATION
- TEMPERATURE
- KINETICS
- MICROSTRUCTURE
- HFB2
OECD FOS+WOS
- 2.05 MATERIALS ENGINEERING
- 2.05.PZ METALLURGY & METALLURGICAL ENGINEERING