Color Laser Marking: How Does it Work?

laser against steelColor laser marking is one of the many ways of putting permanent marks on different types of stainless steel. Unlike etching, color laser marking creates a distinct colored mark when they heat the steel surface. The heat catalyzes the formation of a visible oxide layer.

The color of the stain depends on the surface’s treatment and what went into making the material you are marking. This technique can be used in laser marking for stainless steel, titanium and chrome surfaces. The most common colors in color laser marking are gray, dark brown, and black.

Color Laser Marking Doesn’t Remove Material

Since color laser marking doesn’t remove any material from the target surface, it is always a perfect solution to thin surfaces or in applications where you don’t want a blemish on the material’s surface.

Attaining an even mark depends on the laser’s peak power and pulse frequency. A higher pulse frequency and low power settings are a great idea since the laser only heats the material and does not vaporize it. Too much power or too low a frequency would result in burnt off materials from the surface, which could lead to an etched effect.

Curves Surface Mess up the Laser’s Settings

Since your laser machine uses lenses to focus the light, any slight change in the distance between the focus lens and the target surface could have a considerable impact on the product. While slight changes in laser power are tolerable in laser etching, color laser marking needs perfect uniformity and precision.

A slight deviation in laser power as the beam moves around the radius and goes out of focus will create an irregular mark. Compensating for the changes could lead to partial etching on the areas closest to the beam.

Knowing the simple balance between pulse rate and laser power in color laser marking is crucial to getting that even mark. You can control the heat by making pulse width longer or shorter. Playing around with pulse width and frequency will help give you a perfect oxide layer that gives a solid color mark to the eye.