2011 年 75 巻 9 号 p. 502-508
Argon ion sputter etching was applied to three kinds of tool steels at a radio frequency power of 50 W to 250 W for 0.5 ks to 16.2 ks. Pillar-shaped protrusions with diameters or widths of 100 nm to 1 μm were formed on the surface of SKH51 and SKD5 steel plates, and conical protrusions of similar size were formed on the surface of the SKD61 steel plate. The size of both types of protrusions was typically comparable to the wavelength range of visible light, i.e. 400 nm to 800 nm. The absolute reflectance of the SKH51 steel surface was about 0.3% with a sputter power of 200 W and a sputter etching time of 10.8 ks. The reflectance is nearly constant and is independent of the 400 nm to 800 nm wavelength and incident angle of less than 60°. This indicates that sputter etching of tool steels can produce satisfactory anti-reflection bodies with excellent mechanical properties.