Structure-involved Critical Alloy Design Strategy for Enhancing Antioxidation Performance of Porous Fe-Cr-Al Materials

Porous Fe-Cr-Al samples with different compositions and pore structures were prepared by reactive synthesis. Oxidation tests for porous Fe-Cr-Al materials were performed in static air at 800 °C for 25h to reveal the relationship between alloy composition and corresponding oxide film types, and clarify the influence of pore structure on the critical contents of film-forming elements. The results revealed that near the critical Al content, an alumina-enriched oxide film was formed on the samples, which provided excellent resistance against oxidation, spalling and cracking. Porous Fe-Cr-Al alloys with higher specific surface areas deserved higher critical Al content.