Difference between AC / DC electrolytic marking & etching

When it comes to the electrochemical method, marking and etching are performed with the help of mild electrolytic fluids and electricity. Depending on the electrical current (AC or DC) used, marking and etching give different results and affect the

AC ELECROLYTIC MARKING

Typically, the result of AC marking is a dark oxidized mark on the surface of most metals – stainless steel included.

In most cases, the process only affects the color of the topmost layer of the surface – where the stencil was positioned and the pressure was applied with the help of the marking head.

If performed properly, electrolytic marking leaves the structure of the steel undamaged and causes no corrosion. The resulting mark is crisp, high-definition, and permanent – it can only be removed mechanically through grinding.

The mark may only fade if the surface of the metal comes into contact with strong acids and chemicals.

DC ELECTROLYTIC MARKING

Unlike the AC process, DC etching/marking removes a portion of the upper metal layer and results in an incised light/white mark on the metal surface.

NOTE: Depending on the metal used, AC and DC marking & etching can yield very similar results. For example, aluminum will in both cases provide results that appear to be white.

The etching depth is majorly influenced by the duration of the etching process and the strength of the machine (power unit) used. Typical figure is usually around 0, 0003 of an inch (0, 0076 mm) but this can be adjusted based on different production needs.

As the process involves removal of some of the upper metal layer, it is very important to preserve the molecular stability and ensure that no deformations of the metal surface occur.

This is partially guaranteed by using a DC electrical current instead of the AC one (employed for dark marking). In addition to this, it is recommended to always use material-specific etching acids for consistent and clear results.

WHAT EQUIPMENT TO USE:

Cougartron has developed of practical solutions for electrolytic marking and etching.

Our MK12 marking machine is ideal for smaller workshops and industrial environments.

We are also offering etching kits for our weld cleaning models to make them capable of marking and etching.

Need more information?

Visit our website: www.cougartron.com or contact us via email: sales@cougartron.com