Laser is most effective on metal, where it’s easier to achieve diversified results.
Laser marking and engraving on metals guarantee a precise and clean result. Laser markers also allow for optimization of production times. There is no more efficient technology than lasers at an industrial level. Laser marking is a non-contact process, which does not require any pre- or post-marking intervention.
With laser marking, the metal component is not damaged and the mark is resistant to acids and other corrosive chemicals.
Fiber lasers are the best laser technology for laser marking of metals. They are ideal for laser marking, micromachining, and cutting all metals and alloys. Moreover, they are ideal for painted metals and surface-treated metals (e.g. anodized aluminum).
Fiber laser can be used in both the standard version and MOPA (i.e. variable pulse) version. The latter is particularly effective in terms of versatility and quality.
MOPA laser offers the same advantages as traditional fiber, namely:
It also offers additional advantages for laser marking of both plastics and metals. MOPA laser can produce colored markings on steel and black markings on anodized aluminum. Laser marking is less prone to corrosion (due to limited heat transmission). Laser engraving edges have fewer burns.
MOPA laser guarantees high-contrast laser markings on plastics. Impulse duration control means more uniform, burn-free marking.
Nonetheless, traditional fiber laser still offers very high quality marking on natural aluminum or die-castings.
There are various processes that can be applied to metals, including surface laser marking, deep laser engraving, and annealing.
This process allows markings that are only a few millimeters deep. Compared to laser engraving, less energy converges to the laser beam and the process is faster since it does not need to dig deep. Once in contact with the material, the laser marking melts it at the surface, modifying its roughness.
Unlike marking, which creates grooves, laser engraving evaporates the material in a few milliseconds to create permanent markings. Moreover, engraving is more resistant. It is therefore recommended when the marked component undergoes post-process stress (such as sandblasting for die-castings).
Annealing occurs when the laser marking oxidizes the surface of metals, heating them locally. The oxide layer is usually black, but it can have different shades depending on the temperature of the heated layer. During the annealing process, the material’s surface is kept uniform. This happens because marking involves only heating and not the removal of material. Color reaches a depth ranging between 20 and 30 µm.
The most common metals for laser marking are:
Metal is the most commonly laser-marked material. Metal products make up the bulk of the entire automotive supply chain. A large number of metallic components are also used in the hydraulic and medical sectors.
Traceability requires the marking of identification codes, most commonly the QRcode AND the DataMatrix code. LASIT laser markers use our FlyCAD proprietary software to create codes with extreme versatility.
The software is easy to use and allows automatic data management, by connecting directly to the customer’s MES-ERP system.
LASIT laser markers can also be integrated with an internal vision system for verification and grading of the marked codes. A single station in the production chain ensures product traceability through advanced automation and experience.
All laser marking and engraving methods have one thing in common: the laser beam is pulsed, releasing energy at specific intervals. The difference lies in the speed and line spacing, which determine the distance between each pulse.
In marking, the laser melts the material through heating and modifies its shape to imprint a permanent code or mark. Laser engraving, on the other hand, vaporizes the material. The laser beam penetrates deeper into the surface and removes the upper layers by sublimating them, or rather through a direct transition from a solid to a gaseous state.
This difference is not immediately obvious to many, but for laser marking experts it is very important.