Defect types and defect properties in FeAl alloys

摘要: Abstract The thermomechanical behavior of high temperature intermetallic alloys is related to point defects and their concentration. Positron annihilation a sensitive tool obtain various information about defect properties. In the FeAl system formation enthalpy decreases from 1.6 2.0 eV in pure α -Fe 1.37 (Fe–7at.%Al) 0.91eV D0 3 structure. Additionally, volume increases 0.88 Ω Fe–7at.%Al 1.42 Fe–40at.%Al (Ω=mean atomic volume). change indicates different types defects. quenching experiments migration measured using fast Doppler broadening technique changes 0.5 1.2 eV. Furthermore, knowledge positron lifetimes gives an additional hint main positions lattice. results suggest that thermal B2 phase are mainly triple at low double vacancies higher temperatures. A2 as well structure single supposed be predominant types.