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 25 h to reveal the relationship between alloy composition and corresponding oxide film types and the influence of pore structure on the critical contents of film-forming elements. The results revealed that near the critical Al content, a alumina-type oxide film was formed on the surface of samples, which provides excellent resistances to oxidation, spalling and cracking. Porous alloy samples with higher specific surface areas deserve higher critical Al content.