Study of scratching Mg-based BMG using nanoindenter with Berkovich probe

Nano-scratch tests using nanoindenter with a Berkovich probe are applied to examine the scratch resistance of Mg-based bulk metallic glass (BMG). To realize nano-scratch behavior, a theoretical model of abrasive wear-resistant action on Berkovich is developed to determine the wear behavior. The experimental results of friction force are carried with the application of extensive normal forces. First, a low normal force (5 mN) is applied on Berkovich at different scratch velocities to observe its effect on Mg-based BMGs. The experimental result shows that the dominating wear phenomenon is the rubbing and/or ploughing mode when a slightly normal load is applied. Second, varied normal forces (5-400 mN) are applied on Berkovich at a constant scratch velocity. The experimental result shows that wear mode changes to cutting mode when the applied normal force rises. The indented depth increases when the applied normal force increases. Residual chips appear during the scratch test when the indented depth is about 1300 μm under the normal force of 200 mN. In this study, theoretical models of the forces such as tangential, friction and normal forces are analyzed.