HOW DOES LASER ENGRAVING WORK?

What is laser engraving and how does it work?

Laser engraving is a process that vaporizes materials into fumes to engrave permanent, deep marks. The laser beam acts as a chisel, incising marks by removing layers from the surface of the material. The laser hits localized areas with massive levels of energy to generate the high heat required for vaporization.


To choose the right laser marking process, you should rely on three factors:




The markings resistance: the capacity to remain legible under harsh conditions




The laser marking speed: the marking time that prevents production bottlenecks




The material being marked: its compatibility with the marking method




Small Laser Engraving Machine is typically used to engrave metal workpieces that will be exposed to various types of wear or surface treatments. Metal engraving works with steel and aluminum (including anodized and die-casting aluminum).


The most outstanding feature of this process is its ability to engrave 2D codes that keep high readability rates after post-process treatments. Those treatments can include shot blasting, e-coating and heat treatments, addressing the most complex traceability issues.


But if engraving the most resistant identifiers is not needed, laser etching is generally preferred because it’s a high-speed method that does not rely as heavily on ablation.






From Solid to Gas: How It Works


Whereas laser etching melts the material surface to change its roughness, Laser Engraver sublimates the material surface to create deep crevices. This means that the surface instantly absorbs enough energy to change from solid to a gas without ever becoming a liquid.


To achieve sublimation, the Portable Laser Engraving Machine system must generate enough energy to allow the material’s surface to reach its vaporization temperature within milliseconds. Considering the extreme temperatures required for sublimation, laser engravers are pretty powerful tools.


Materials are vaporized into fumes when they reach this temperature. As a result, when you buy a laser system, it should always come equipped with a fume extraction system to protect the work environment and an air knife to protect the laser’s lens.


Fiber lasers are the ideal engraving tools for this because they generate a wavelength that reacts well with metals.






Find a Laser Engraving Machine


If you are looking for a Laser Engraving Machine, this list will help you find the right laser:




To integrate custom solutions yourself or with an integrator, view our OEM marking systems, including multiple types of lasers for industrial applications. Our range of laser systems includes fiber lasers and CO2 lasers.




For turnkey automated or semi-automated laser solutions, consult our integrated laser machines page.




To find information specific to the metal you’ll be marking, scroll through the list of metals.




If you need guidance, you can always ask an expert.








Why lasers are used for cutting


Lasers are used for many purposes. One way they are used is for cutting metal plates. On mild steel, stainless steel, and aluminum plate, the Laser Cutting Machine is highly accurate, yields excellent cut quality, has a very small kerf width and small heat affect zone, and makes it possible to cut very intricate shapes and small holes.


Most people already know that the word “LASER” is actually an acronym for Light Amplification by Stimulated Emission of Radiation. But how does light cut through a steel plate?






How it works


The laser beam is a column of very high intensity light, of a single wavelength, or color. In the case of a typical CO2 laser, that wavelength is in the Infra-Red part of the light spectrum, so it is invisible to the human eye. The beam is only about 3/4 of an inch in diameter as it travels from the laser resonator, which creates the beam, through the machine’s beam path. It may be bounced in different directions by a number of mirrors, or “beam benders” before it is finally focused onto the plate. The focused laser beam goes through the bore of a nozzle right before it hits the plate. Also flowing through that nozzle bore is a compressed gas, such as Oxygen or Nitrogen.


Focusing the laser beam can be done by a special lens, or by a curved mirror, and this takes place in the Wood Laser Cutting Machine head. The beam has to be precisely focused so that the shape of the focus spot and the density of the energy in that spot is perfectly round and consistent, and centered in the nozzle. By focusing the large beam down to a single pinpoint, the heat density at that spot is extreme. Think about using a magnifying glass to focus the sun’s rays onto a leaf, and how that can start a fire. Now think about focusing 6 KWatts of energy into a single spot, and you can imagine how hot that spot will get.