Nanoindentation Study on Room-Temperature Creep Behaviour of Ir33ni28ta39 Bmg with a High Glass Transition Temperature

In this study, the Ir 33 Ni 28 Ta 39 bulk metallic glass (BMG) is used as the object and the influence of different loads and loading rates on the room-temperature creep behaviour of Ir 33 Ni 28 Ta 39 BMG are investigated using nanoindentation technology. The results show that the nanoindentation hardness decreases with an increase in the load, which is consistent with the indentation size effect characteristics of the Nix–Gao model. Regarding the influence of loading rate on nanoindentation hardness, there is a negative correlation, however, the influence on nanoindentation hardness is insignificant. Combined with the analysis of the creep displacement curve and the stress index, it can be found that the room-temperature creep performance of Ir 33 Ni 28 Ta 39 BMG is insensitive to the loading rate. Serrated flow characteristics are observed from the creep displacement curve, indicating a relationship between the soft zone representing the weak bond and the hard zone representing the strong bond in the iridium-based BMG. The serrated flow that appears on the creep displacement curve is caused by the difference in the resistance of the shear transition zones during the movement process. The creep deformation mechanism is discussed in considering “shear transformation zone” which explains the serrated flow in the BMG