Figure 9

The worn-out surface of the (a) base material (b) Cu + 5% HEA, (c) Cu + 10% HEA, and (d) Cu + 15% HEA surface composites tested under mild conditions (L = 10 N, S = 0.5 m/s, D = 1000 m).

The worn-out surface of the (a) base material (b) Cu + 5% HEA, (c) Cu + 10% HEA, and (d) Cu + 15% HEA surface composites tested under mild conditions (L = 10 N, S = 0.5 m/s, D = 1000 m).