A Rapid Technique for Preparing Thin Foils for Electron Microscopy (Improved Jet-Polishing Method)

This rapid electropolishing technique consists of two processes, namely first jet-polishing and fiinal thinning and can be applied to a initial specimens as small as 3 mm in dia. and 0.1 mm thick. (1) Jet-polishing : The center region of the disc is thinned by jet-polishing using a stationary jet. The jet-polished area at the disc is about 2 mm in dia. and the thickness is reduced to about 30 μ. The jet-polishing time is one or two minutes. (2) Final-thinning : The electropolishing is carried out for uniform polishing of the center region of the jet-polished area. Thus, the selected area of specimen can be polished within five minutes. This rapid technique has been used for many metals and alloys (Ag, Al, Al-Cu, Co, Cu, Cu-Zn, Fe, Low carbon steel, Stainless steel and Ta), and the best condition for each material was determined.