What’s 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.
In this article, you’ll find in-depth information on how laser engraving works and how to find a laser engraving machine.
But first here’s a short video that shows a fiber laser engraving process in action. In this video, you’ll see the high-quality contrasts, the marking speed, and the fumes generated during laser marking.
To choose the right laser marking process, you should rely on three factors:
Laser engraving technology 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 shotblasting, e-coating and heat treatments, addressing the most complex traceability issues.
But if engraving the most resistant identifiers isn’t needed, laser etching is generally preferred because it’s a high-speed method that doesn’t rely as heavily on ablation.
You can laser etch a wider variety of materials, including steel, aluminum, anodized aluminum, lead, magnesium, and zinc.
There’s also a unique method called laser annealing to mark metals like stainless steel.
Whereas laser etching melts the material surface to change its roughness, laser engraving sublimates the material surface to create deep crevices. This means that the surface instantly absorbs enough energy to change from solid to gas without ever becoming a liquid.
To achieve sublimation, the laser engraving 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.
| Material | Vaporization Temperature |
|---|---|
| Aluminum | 2327°C |
| Copper | 2595°C |
| Iron | 3000°C |
| Lead | 1750°C |
| Magnesium | 1110°C |
| Zinc | 906°C |
Source: "Corrected Values for Boiling Points and Enthalpies of Vaporization of Elements in Handbooks"
Note: For metal alloys (such as steel), vaporization temperatures vary according to the alloy's composition.
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.
If you look at the following magnified images, you can see the chaotic surface created as a result of laser engraving.
Before Laser Engraving  | After Laser Engraving  |
Permanent marks created by laser engraving are darker because light is trapped in deep crevices (the engraving depth can reach up to 0.5 mm).
There are two ways of creating contrast when you laser engrave a surface.
The first (and faster) engraving method creates contrast between the bare material and the black marks that are engraved. This method is only recommended if the bare material color is pale enough to generate a high contrast.
The second (and longer) engraving method achieves higher quality contrasts because it etches black and white marks. With this method, the laser system uses both laser engraving (to create the black marks) and laser etching (to create the white marks).
If you’re looking for a laser engraving machine, this list will help you find the right laser:
Apart from etching and engraving, other laser technologies can be used to mark logos and identifiers like barcodes and serial numbers.
If you want to know what sets them apart, you may find the following posts interesting:
Jerome has been working in the high tech industry for at least 10 years, with a background in physics and physical engineering. He has hands-on experience with laser processes, their interaction with materials, and industrial traceability standards.
Permanent part marking ranges from logos and serial numbers to barcodes and certification marks. It’s a critical step in manufacturing as a way to maintain control over quality, comply with regulatory requirements, and ensure the traceability of products.
For industrial laser marking, high-speed lasers are essential to meet tight production schedules while maintaining high-quality standards. But with so many options available, choosing can be confusing. After all, you want a machine that not only performs at high speeds, but that is also cost effective.
Laser marking is the first choice when manufacturers need to improve their traceability capabilities. Fiber laser technology is recognized as the best option when it comes to permanent markings, high-contrast codes, post-process resistance, and ease of integration.
