High-temperature oxidation behavior and pore structure of porous TiAl3 intermetallics at 650 °C to 900 °C

Abstract

Porous TiAl3 materials were prepared by a time- and energy-saving thermal explosion (TE) method with Ti-75 at% Al mixture powders. Cyclic oxidation tests were performed in air at 650 °C, 800 °C, and 900 °C. Only a weak peak of the oxide phase was detected by X-ray diffraction when the oxidation temperature was below 800 °C. The pore structures remained stable without pore blockage or collapse due to the thin protective oxide layer formed on the surface of the product skeleton at 650 °C, which was confirmed to be Al2O3. The thickness of the oxide scale increased with increasing the oxidation temperature from 800 °C to 900 °C. The compressive strength of the oxidized sample was inversely proportional to its corresponding porosity. Additionally, the antioxidant mechanism at high temperature was further investigated, indicating excellent oxidation resistance. Therefore, porous TiAl3 intermetallic can be considered as promising materials for applications such as filtration, separation, and catalysis at a high temperatures up to 800 °C.

Keywords

• Porous materials
• Thermal explosion
• Sintering
• Microstructure
• Oxidation resistance