Fabrication of oxide powder from Fe–46Ni alloy scrap

Abstract

The oxidation behaviour of Fe–46Ni alloy scrap was studied in 0.2 atm oxygen partial pressure at the temperature range of 400–900°C. The oxidation rate was found to be increased with increasing temperature and followed parabolic rate law linearly proportional to temperature. Microstructure and a cross-sectional area of the oxide layer were examined by scanning electron microscope, energy dispersive spectrometryand X-ray diffraction and it may be predicted that iron ions and electrons migrated outward and oxygen anion diffused inward through a spinel structure, (Ni, Fe)₃O₄. In the long run, oxide powder less than 10 μm from Fe–46Ni alloy scrap was obtained using ball-milling and sieving processes and recovery ratio approached up to 95% for 15 hours.

Keywords:

• Fe–46Ni
• Oxidation rate
• Parabolic rate law
• Spinel structure
• Recovery ratio
• Alloy scrap