Laser engraving on metal is an advanced processing technology that is characterised by its ability to create deep, permanent marks on the surface of metal materials. Unlike laser marking, which is often limited to a superficial alteration, laser engraving physically removes part of the material, creating grooves and cavities that are not only visible but also perceptible to the touch.
This technology is based on high-power lasers, typically fibre lasers, which allow engravings with varying depths, from a few microns up to several millimetres. The precision of the process, combined with the possibility of accurately controlling the depth of the engraving, makes this technique particularly suitable for applications requiring permanent and resistant material modifications.
Distinctive features of laser engraving on metal include:
- Creation of deep, defined grooves
- Permanent and wear-resistant result
- Possibility of complex, three-dimensional designs
- Precise control of engraving depth
- No mechanical contact with the surface
- Absence of mechanical stress on the material
How does it work?
The process of laser engraving on metal is based on the use of a high-power laser beam that, concentrated at a precise point, vaporises the metal material. The laser beam, typically generated by a fibre laser, is focused on the surface with extreme precision, reaching temperatures above the melting point of the metal. The main difference to simple marking lies in the power and interaction time of the laser with the material:
- The laser progressively removes layers of material
- The depth of the engraving is controlled through multiple passes of the laser
- The system can modulate power and speed to achieve different depths and finishes
- The process generates a three-dimensional cavity that is visible and perceptible to the touch
LASIT and 3D laser engraving
A particularly advanced aspect of laser engraving on metal concerns the processing of three-dimensional surfaces. In this field, the technology must overcome two fundamental limits: the physical one, related to the inclination of the laser beam, and the mechanical one, determined by the Z-dynamic stroke. When the laser beam hits the surface perpendicularly, it generates a circular spot with maximum energy concentration, thus ensuring maximum incisiveness on the material. However, when the angle of incidence deviates from perpendicularity, the spot becomes increasingly elliptical in shape, reducing the energy density and, consequently, the depth of the engraving. In order to overcome these limitations, the most advanced systems use technologies such as ‘3D Wrapping’ combined with ‘Z-Dynamic’, which make it possible to maintain optimum focus on all points of the surface and to achieve geometrically perfect engravings even on complex shapes such as cylindrical, truncated cone or hemispherical surfaces.
LASIT is able to offer state-of-the-art solutions that allow precise, in-focus marking even on cylindrical components or non-planar surfaces.
Easy-check: Laser engraving for wear monitoring
One of the most innovative applications of laser engraving on metal is monitoring the wear of mechanical components. In this field, laser technology allows calibrated engravings with tolerances in the order of a few microns. An emblematic example is the use of picosecond fibre lasers, which, thanks to their extremely short pulse duration (3 picoseconds), enable extremely precise and controlled engravings to be obtained, without creating thermally altered areas or material remelted on the surface. This micrometric precision opens up new scenarios in the field of quality control and predictive maintenance, making it possible to monitor the wear of metal components with a level of accuracy previously impossible to achieve. This is why LASIT developed the Easycheck application, currently used in the automotive sector for brake discs.
The Easy Check is a ‘calibrated’ engraving directly on the braking track of the disc. Depending on the type of brake disc, the Easy Check is engraved with a specific target depth (usually between 50 and 100 µm) and with tolerances in the order of a few microns. It is also possible to carry out several EasyChecks at different distances from the disc hub in order to monitor any unevenness in wear, just as it is possible to engrave at different depths in order to gradually understand the state of wear of the disc.
Laser engraving of cast components: resistance after sandblasting
Laser engraving on metal has a particular place in the automotive and foundry industries. Being deep and therefore highly resistant, engraving is suitable in these sectors where components are continuously subjected to high stress.
LASIT has developed a system whereby engraving is legible even after invasive processes such as sandblasting and shot peening. Thanks to specific parameters that are set, and high-power lasers (such as 100W, 200W and 300W fibre), we can provide turnkey solutions that are ideal for the casting industry, guaranteeing complete traceability of components.
