Laser engraving on metal, how it works

Laser engraving on metal is a process that uses a focused laser beam to remove material from the surface, creating precise and detailed engravings. 

The laser, through the concentrated energy of a beam of light, interacts with the metal to permanently engrave the piece. Let's better understand in detail how this process works:

• How the laser is generated

A laser device (fibre laser or a diode laser), produces a laser beam having an adjustable wavelength depending on the metal to be engraved.

• Laser focusing

The laser beam is then focused using a system of lenses or mirrors, concentrating it in a small spot on the surface of the metal so as to obtain an engraving.

The greater the focus of the beam, the greater the accuracy and quality of the drawing. 

• Laser absorption

When the laser beam meets the metal surface, a portion of the laser energy is absorbed by the material and transformed into heat, thereby generating a melting or vaporization point.

The choice between melting and vaporization depends on the power of the laser, the scanning speed and the properties of the metal. In cases such as aluminium, copper, or brass, where the metal has a low melting temperature, the laser energy can cause the material to melt. In other cases, when the metal has a higher melting temperature (such as stainless steel or titanium), the laser energy can vaporize the material directly without going through the melting state.

• Parameter control

When laser engraving on metal, it is essential to carefully check the laser parameters for optimal results. This includes laser power, scanning speed, laser pulse rate, and focus. These parameters may vary depending on the characteristics of the metal, such as its thermal conductivity, hardness, and other specific properties.

• Cooling and finishing

After laser engraving, it is important to allow the metal to cool to avoid any distortion or damage. Subsequently, the piece of metal can be subjected to further finishing processes, such as sanding or polishing, to obtain the desired final effect.

Metallic materials and differences 

Laser engraving on metal has become an increasingly widespread and popular technology. This engraving method offers superior precision, speed and flexibility compared to traditional mechanical engraving methods.

Let's discover together the types of metal materials on which it is possible to print and the differences in construction.

• Stainless steel

Stainless steel is one of the most widely used materials in laser engraving, thanks to its corrosion resistance and durability. It is also often used in sectors such as the automotive industry, aviation, and mechanical engineering, as it is able to produce clean and well-defined engravings.

• Aluminium

Aluminium is a light metal widely used in industries such as electronics, aerospace, and automotive. Laser engraving on aluminium can produce high-quality engravings, but due to its high thermal conductivity, aluminium often requires higher laser power to achieve optimal results.

• Copper

Copper is a highly conductive material, mainly used in electrical and electronic applications. Laser engraving on copper can be more complex than other metallic materials due to its high thermal conductivity. For these reasons it is important to know how to manage the settings of the laser and its parameters.

• Titanium

Titanium is a material known for its lightness and corrosion resistance. It is often used in the aviation, medical and energy industries. Unlike copper, laser engraving on titanium requires greater laser power, due to its high thermal resistance. 

Conclusions

Laser engraving on metal offers a wide range of possibilities in the processing of metal materials. The choice of materials will influence the laser parameters and settings needed to achieve precise, high-quality engravings. It is critical to consider the differences in metallic materials in terms of hardness, thermal conductivity, chemical reaction, processing speed, and engraving behaviour. With a correct understanding of these factors and a careful adjustment of the laser parameters, it is possible to achieve optimal results in engraving on the metal.