Electrochemical marking is recognised as the only method of marking metal without distortion, which is why it is still the only option for many applications including some critical aero-engine components, surgical implants and thin walled section parts. It was used in the early days to mark some components on the Apollo 11 lunar module and also some components on Concorde.
Back in the late sixties, our electrochemical marking systems had gained universal acceptance within the aircraft industry for the marking of engine components, undercarriage and airframe parts, particularly due to the fact that the marking process had no measureable detrimental effect on the mechanical properties of the material.
Early success was achieved through specific expertise in the chemical and photographic fields which was particularly relevant where high quality electrolyte solutions and stencils were central to high quality marking. This is still true today although the process has been developed significantly since then delivering fast, clean, high quality precision marking with long term proven reliability.
Electrochemical marking is permanent because it is created by etching out metal and then plating on the etched surface a stable compound of the base metal. In most cases this is an oxide, giving a high contrast black mark on many metals. A below surface etch mark can also be achieved or a combination of the two.
Marks are produced extremely quickly between 0.25 and 4 secs for most metals. Deep etching takes a little longer but marks can be deep enough to be read through paint. The mark can only be removed by vigorous abrasion but the mark will remain until one ten-thousandth of the metal has been removed.The process is environmentally friendly as it uses water based electrolytes and neutralisers .
The marking unit regulates the etching power and most units in UMS’s ME3000 range are fitted with a timer to help give consistency of mark regardless of the operators experienceWithin Automotive, Electrochemical marking is still accepted as the only accurate and economic method of producing strain grid patterns on metal blanks for the study of their forming properties for strain grid analysis. Here long life photographic stencils are used which carry a pattern of small circles or dots, and are arranged in either a close packed or interlocking pattern.
The electrochemical mark leaves a pattern on the surface of the metal. The deformation of the circles into ellipses or the spread of the dots during sheet metal forming operations reproduces the surface strains created. This gives an immediate visual indication of the direction of the metal flow and the magnitude of the strains. Still today many large car manufacturers and universities are using UMS’s ME96 Strain Grid Unit for this type of application.
The nineties saw the introduction of two dimensional datamatrix barcoding for marking jet engine components within Aerospace. “Cradle to grave” traceability was needed and UMS developed a software driven system which enabled the creation of datamatrix codes to meet this type of application. The software was fully featured and contained a great deal of control and security. Once the datamatrix code and/or human readable text had been created, it was output to a 300dpi quality thermal printer utilising a brand new type of instant stencil paper. The software downloaded the correct marking settings to the marking unit to eliminate the possibility of operator error. This revolutionised electrochemical marking and with ongoing refinement of stencil creation we now have packages suitable for very sophisticated applications as well as every day general engineering ones.
Complete self contained systems allow the user to create their own stencil and apply the mark to the component all at one small workstation area.More recently the ME3000PC automated system has been introduced which takes automated electrochemical marking to a new level. The stencil is created and automatically fed to the marking destination so the operator only has to place the component and press a button to create a mark. This now for the first time allows automated sequential numbering or batch marking in both human readable text and 2d datamatrix and QR code formats.
Electrochemical marking continues to offer an extremely, reliable, low cost, high quality marking system with the versatility to mark both the smallest component right up to the largest fabrication whether it be cylindrical, thin walled or even fully hardened steel often with faster marking speeds than laser. It shows such versatility that it is widely used across the whole of industry including Aerospace, Automotive, Hand Tools, Oil & Gas, Engineering Components, Surgical equipment and many more. Universal Marking Systems Ltd manufacture and supply, globally, a range of electrochemical marking equipment and accessories under the Metaletch brand name.