Electropolishing electrolytic polishing

Figure 1.3. Illustration of the two-stage electropolishing process for the production of FIM specimens. In Stage 1 a 5-7 mm thick layer of electrolyte is floated on a denser inert liquid, producing a necked region in the centre of the blank. In Stage 2, polishing is continued until the weight of the lower half of the specimen blank is too heavy to be supported by the thin neck. (After Miller et al. 1996.)...

Electrochemical metal removal processes have been developed and utilized by industry for a variety of different applications. Electropolishing as an industrial finishing operation was first demonstrated by Jaquet in 1930 [113]. Metals such as aluminum, steel, brass, cooper, and silver/iuckel alloys are anodized to produce a highly reflective mirror fliush. The surface to be polished is the anode with a current density in the range of 0.100 to 0.800 A/cm. The electrolyte is typically phosphoric... 

The oxidation of trivalent chromium oxide to hexavalent oxide is also observed in passive films on stainless steel. An interesting application of this effect is electropolishing. The object made of stainless steel to be polished is connected as the anode in an electrochemical cell that contains a suitable electrolyte, normally a mixture of concentrated sulfuric and phosphoric acids. Transpassive dissolution then leads to electropolishing, provided the dissolution reaction is under mass transport control. Protrusions on the surface are favored by mass transport and therefore they dissolve more rapidly, leading to leveling of the surface [34]. 

In many applications, a polished finish is desirable on machined components. The production of an electrochemically polished surface is usually associated with the ran cbm removal of atoms from the anode workpiece, the surface of which has become covered with an oxide film. This is governed by the particular metal electrolyte combination being used. (Nonetheless, the mechanisms controlling high- current density electropolishing in ECM are still not completely understood.)... 

Electropolishing is another method to prepare TEM specimens for certain samples, particularly metallic specimens. Electropolishing is a process in which the sample (anode) is polished by electrochemical action, by dissolving it in an electrolyte and applying a suitable potential. The electrolyte, its temperature and bias voltage are some of the important parameters in controlling the rate of dissolution of the sample. 

Polishing, electropolish (surface modification) Polishing a surface that is the anode of an electrolysis cell using a suitable electrolyte. Example Electropolishing stainless steel in a phosphoric acid-based electrolyte. 

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