FeAl Base ODS Alloy Fabricated by Solid State Reduction of Mill Scale Powder

Abstract

Powder mixture of Fe, Al and mill scale Fe power (24.5 mass% O) was milled for certain period. Powders were mixed to become the composition of Fe-40mol%Al + 0, 2.5, 5.0, 7.5, 10.0 vol% Al₂O₃ after mechanochemical reaction. Longer time milling over 1080ks, FeAl phase newly formed only by MA. Al acts as a reducing agent for Fe oxide (mill scale powder) and then synthesizes Al₂O₃. The mill scale powder affected the MA process and phase formation behavior. Almost full density compacts were obtained by vacuum hot pressing under the condition of 1273K-150MPa-3.6ks, and those become FeAl intermetallic compound. Compacts, made with adding high weight percent of mill scale powder, showed higher hardness compared with the case of FeAl monolithic compact. This is presumably resulting from the effect of dispersed Al₂O₃ introduced by mechanochemical reaction during MA and later consolidation process.