Non-Equilibrium Solid Solution Phase Formations by High Energy Electron Irradiation in UHVEM

Satoshi Anada and Hidehiro Yasuda

Abstract: High-energy-electron-irradiation-induced microstructural changes in intermetallic compounds Cr₂Al, Ti₂Pd, Cr₂Ti and CrFe, which have solid solutions as equilibrium phases in the high-temperature regions in the thermal-equilibrium phase diagrams, have been investigated systematically by in situ observation technique in an ultra-high voltage electron microscope. All of these intermetallic compounds, under electron irradiation, are found to transform into solid solutions in various ways. It has been indicated that dominant factors of the electron-irradiation-induced non-equilibrium solid solution formations are related to their thermal-equilibrium phase diagrams and their crystal structures, and solid solution nucleation can be induced by defects introduction, leading to an increase in free energy.

Key words: In situ observation, UHVEM, Electron Irradiation, Solid State Phase Transition