(a)
(b)
(c)
(d)
(e)
(f)
Figure 13: Effect of sliding velocity on worn surfaces of the investigated PA 6.6: ((a) and (b)) shallow scratches and wear traces of adhesive nature; (c) scratches and cracks on the surface; (d) smooth zone with dominating adhesion and microcutting; (e) zone with fracture; bridges with plastically deformed pores between them; (f) zone with fracture, SEM.