Plastic deformation in Ce-based bulk metallic glasses during depth-sensing indentation

Abstract

The deformation behavior and the effect of the loading rate on the plastic deformation features in (numbers indicate at.%) Ce 60Al 15Cu 10Ni 15, Ce 65Al 10Cu 10Ni 10Nb 5, Ce 68Al 10Cu 20Nb 2, and Ce 70Al 10Cu 20 bulk metallic glasses (BMGs) were investigated through nanoindentation. The load–displacement ( P– h) curves of Ce 65Al 10Cu 10Ni 10Nb 5, Ce 68Al 10Cu 20Nb 2, and Ce 70Al 10Cu 20 BMGs exhibited a continuous plastic deformation at all studied loading rate. Whereas, the P– h curves of Ce 60Al 15Cu 10Ni 15 BMG showed a quite unique feature, i.e. homogeneous plastic deformation at low loading rates, and a distinct serrated flow at high strain rates. Moreover, a creep deformation during the load holding segment was observed for the four Ce-based BMGs at room temperature. The mechanism for the appearance of the “anomalous” plastic deformation behavior in the Ce-based BMGs was discussed.