Application

Electro-polishing

Principle:

The state of the surface determines the appearance, function and life of metal parts. Polishing and electrochemical deburring (electro-polishing) improve a whole range of the properties of metal surfaces.
The application of a direct current causes the dissolution of the metal surface on a part connected to the anode pole immersed in a specific electrolyte specific. The dissolution phenomenon is preferably controlled by the micro-irregularities. The surface is graded and becomes shiny, hence we call this electro-polishing.

The macro-geometric structure remains the same but its contours are rounded and the surface undergoes a levelling. The sharp edges and projections are subjected to a stronger attack which enables deburring and micro-deburring of the entire surface. The results are perfectly reproducible which allows the treatment of limited tolerance parts. Electro-polishing causes a release of oxygen, avoids hydrogen inclusions and embrittlement of the parts.

Results:

Metal surfaces having had either electro-chemical or mechanical treatment are fundamentally different. A metal surface subjected to machining, milling, drilling, sanding, polishing, undergoes changes of its original properties. The rise in temperature, the deformation of the workpiece during mechanical treatment causes structural changes, the enlargement of crystals and internal stresses.

In contrast to these techniques, the electro-polishing processes have the effect of removing the surface layers without causing mechanical, thermal or chemical disturbances.

Electro-polished surfaces are:

  • Free of impurities and internal stresses
  • Levelled and free of micro-fissures
  • Chemically passive
  • Free from burrs, chips, flakes, particles and gaseous inclusions
  • Bright and decorative.

Electro-polished surfaces are remarkable for:

 

  • Improved corrosion resistance and increased life span
  • Reduced frictional resistance
  • Ease of cleaning, reduced product adhesion and the risk of microbial germination
  • Reduced risk of radioactive pollution and improved decontamination capability
  • Decreased catalytic surface reactions
  • Ease of surface degassing in ultrahigh vacuum facilities
  • Improved electro-deposition conditions
  • Ease of welding
  • Optimal reflectivity
  • Ease of control due to the removal of disrupted layers and the exposure of machining and manufacturing defects.

Chimiderouil has been active for many years in this area, has become a recognized and valued partner by many companies and has contributed to major projects such as illustrated below: