The Mechanism of Oxide Growth on Pure Aluminum in Ultra-High-Temperature Steam

Abstract

A high-temperature water steam (H2O(g)) between 300 °C and 1000 °C reacted with the Al surface in this study. The Al surface states were characterized and analyzed using XRD °C, XPS, and SEM after and before the reaction, and the effects and mechanism of H2O(g) on the Al surface morphology and chemical composition were studied. The experiment showed that for an Al sheet reacting with H2O(g), its oxide layer morphology changed from nano-needle to flaky and granular oxides gradually with the rise of temperature, and finally the Al surface became porous as a whole. Its oxide crystals were amorphous and were determined to be aluminum oxide (Al2O3) using XPS. The needle-like oxide in the Al sheet surface tended to grow toward the surface, and no obviously inward oxidizing corrosion layer occurred in the aluminum substrate; the oxide layer between the oxide and Al sheet substrate was compact, and could effectively prevent the infiltration and corrosion of water molecules.

Influence of aluminum nanoparticles in epoxy resin and epoxy coating for anticorrosion and antibacterial protection in pipeline industry

“…Both samples after a certain time (10 days of exposure) show a constant mass concentration of aluminum in the wastewater. Pure aluminum has a greater affinity with oxygen and can be automatically oxidized in contact with water media to form an Al 2 O 3 passivation film 38 . The constant value of the mass concentration of aluminum in the wastewater could be the reason for the oxidation of Al NPs on the surface of the epoxy coating, and the release of new Al NPs due to the formation of aluminum oxide is possible.…”

“…Pure aluminum has a greater affinity with oxygen and can be automatically oxidized in contact with water media to form an Al 2 O 3 passivation film. 38 The constant value of the mass concentration of aluminum in the wastewater could be the reason for the oxidation of Al NPs on the surface of the epoxy coating, and the release of new Al NPs due to the formation of aluminum oxide is possible. However, little data is available on the degradation of polymer nanocomposites, and the state of the imbedded nanoparticles during environmental exposures.…”