Even in the case of sliding contact between smooth surfaces of the same ductile material, parallel grooves
are generally found on the wear surface after sliding. The peak and the valley coincide well with the
mating surfaces, as shown in Figure 7.10. This result means that the hard abrasive asperities are formed
on the mating surface because of, for example, work hardening, phase transitions, and third-body
formation at the contact interface during repeated sliding contact. Therefore, abrasive wear is recognized
as a more representative wear mode of ductile material in repeated sliding