2012 Volume 98 Issue 12 Pages 658-666
Six kinds of steels with various thickness smaller than 3mm and SUS304 steel wires with 0.5 and 0.2 mm diameter were etched by argon ion sputtering at a radio frequency power of 100-350W for 0.9-19.8ks. Cone-shaped protrusions with various sizes smaller than 5μm were formed on the surface of SK120, SUS304 and SKD61 steel sheets. These protrusions were formed from the bottom of pillar-shaped carbides that precipitate perpendicular to the surface. When the sheet thickness is very small, the conical protrusions were not formed, but the column- or ringshaped protrusions with various sizes smaller than 1μm were formed on the surface of SUS304, SUS316, SUS316L and SKD61 steels. The reason will be that the precipitation of fine pillar-shaped carbides occurs densely due to a small temperature gradient in the thickness direction and the conical protrusions quickly decay to the column- or ring-shaped protrusions. Also for the SUS304 wire, the fine column- or ringshaped protrusions were formed over whole of the surface due to a roundabout of plasma. The sheets and wires with not only the cone-shaped protrusions but also the column- or ring-shaped ones will give wide and flexible applicability to machine parts and structures revealing many functions.