Efficient atomic packing-chemistry coupled model and glass formation in ternary Al-based metallic glasses

Abstract

An efficient atomic packing-chemistry coupled model has been described for ternary Al-based metallic glasses based upon efficient atomic packing and electrochemical potential equalization principle. For Al-TM (transition metal)-RE (rare earth) system, RE-centered clusters are arranged in a mode of spherical periodic order, and TM atoms locate at the interstitial sites between RE-centered clusters to form an efficient atomic packing. The equalization of electrochemical potential between the RE-centered clusters and the TM-centered clusters accounts for the stability of amorphous structure. Further, complementary inverse structure is utilized to select efficient clusters and solute elements for the best glass-forming ability. The validity of this model was testified in the Al–Ni-RE (Y, Ce, La, Gd) systems. A new Al–Ni–Ho glass with a wedge thickness of about 718 μm has been discovered at the predicted composition.