Mechanical performance of metallic glasses during nanoscratch tests

Nanoscratch experiments on four bulk metallic glasses using a pyramidal diamond tip (Berkovich) indenter have been carried out under different loads and scratching velocities. There exists a general correlation between the hardness and wear resistance, i.e., a lower hardness produces a lower wear resistance. Scratch velocity appears to have little effect on the scratch depths of the four alloys studied. However, faster scratch velocity leads to finer shear bands. Compared with ribbon sample with the same chemical composition, Ti-based bulk glassy sample that experienced slower cooling rate during solidification, and thus contained less free volume, exhibits better wear resistance.