2019 Volume 60 Issue 698 Pages 53-57
Fine piercing of micropatterns into metallic sheets has become an engineering issue in the stamping industries. Plasma nitriding-assisted printing was proposed as a solution for forming a microtextured surface on die materials. AISI420 die material was employed for this plasma printing. First, maskless patterning was used to print two dimensional micropatterns onto a mirror-polished AISI420 stainless steel surface. The unprinted surface area was selectively nitrided; the negative micropattern of the original prints changed to nitrogen supersaturated AISI420 areas. This die surface was dipped into 20% HCl solution for chemical etching. Since the nitrogen supersaturated areas had high corrosion resistance against this etching, only the printed parts were selectively etched, leaving a hardened AISI420 punch head after etching. These selective nitriding characteristics were demonstrated in experiments. A cylindrical punch array with a diameter of 50 mm was fabricated as a punch for piercing microtextures into thin AISI304 stainless steel sheets.