Microindentation of a Zr₅₇Ti₅Cu₂₀Ni ₈Al₁₀ bulk metallic glass

Using microindentation technique, the indentation behavior of a Zr ₅₇Ti₅Cu₂₀Ni₈Al₁₀ bulk-metallic glass is studied over a range of the indentation load from 200 mN to 500 mN. For the indentation load larger than 100 mN, the indentation load-depth curves during unloading display three regions, a) a fast unloading phase at the onset of unloading, b) a linear phase at which the indentation load is proportional to the indentation depth, and c) a slow unloading phase after the linear phase. The size of the linear region increases with the increase in the indentation load, and the slope is independent of the indentation load. The indentation hardness decreases slightly with the increase in the indentation load. The plastic energy dissipated in an indentation cycle is proportional to the 3/2 power of the indentation load. The effect of the indentation loading rate on the indentation behavior is discussed.