Electron irradiation induced phase transformation in Zr66.7Cu33.3 and Zr66.7Pd33.3 metallic glass

Crystallization and phase selection in Zr66.7Cu33.3 and Zr66.7Pd33.3 metallic glass during thermal annealing and electron irradiation were examined. During thermal annealing an equilibrium C11b-Zr2Cu phase directly precipitated in the amorphous phase of Zr66.7Cu33.3 metallic glass while a thermal equilibrium C11b-Zr2Pd phase formed after icosahedral quasi-crystalline phase precipitation in Zr66.7Pd33.3 metallic glass. The amorphous phase was not stable under electron irradiation and metastable crystalline phases with face-centered cubic-based structure formed in both kinds of metallic glass by electron irradiation induced crystallization. The unique phase selection in electron irradiation induced crystallization is due to a change in the phase stability of crystal, quasi-crystal and amorphous phase under electron irradiation.