Figure 4

3D topography of 304 stainless steel before and after EPP with an input voltage of 120 V for different processing time: (a) 0 s; (b) 20 s; (c) 40 s; (d) 60 s; (e) 120 s; and (f) 180 s.

3D topography of 304 stainless steel before and after EPP with an input voltage of 120 V for different processing time: (a) 0 s; (b) 20 s; (c) 40 s; (d) 60 s; (e) 120 s; and (f) 180 s.