Influence of loading rate on the mechanical performance of metallic glass

Amorphous metallic glass Cu47Ti35Zr11Ni6Si1 was investigated by load-control nanoindentation experiments using the cube corner indenter tip over a wide range of loading rates. The indentation hardness was calculated using different methods either from the loading curves or indent area. Pop-in events were observed on the loading part of the indentation curves mainly at lower rates of loading. Instantaneous plastic deformation decreases with increasing loading rate according to a power law. At high loading rate the instantaneous deformation is suppressed by continuous plastic deformation and no well-developed pop-ins are observed. The morphology of shear bands in the pile-up area of indents showed no correlation with the pop-in event population of the nanoindentation curves and the loading rate.