Considerations Regarding Laser Marking on Metal

Both CO2 lasers and fibre lasers are very popular for marking metal with barcodes, serial numbers, and logos.

The long lifetime, low maintenance requirements, and relatively low cost of fibre lasers make them ideal for industrial marking applications. The ink produced by this type of laser is permanent and high-contrast, and it does not decay over time.

CO2 laser engraving can only be carried out on treated metals (or pastes) before engraving. Marking agents are applied to bare metal with CO2 lasers, which create permanent marks. CO2 lasers are also affordable and fast, and they can keep wood, acrylic, and natural stone.

Almost any Windows-based operating system can be used to operate Epilog laser systems.

Differences between lasers

Because different types of lasers react differently with various materials, some considerations must be made.

For instance, CO2 lasers take longer to mark metals since metal marking agents must be coated or pre-treated first. Also, the marking agent needs high power and low speed to bond with the metal. The piece should be run at a slower pace and higher capacity if the mark is easily wiped off after lasering.

Metal can be marked with CO2 lasers without removing material, ensuring its tolerance and strength are not compromised. Furthermore, painted brass and anodized aluminium do not need pre-treatment.

Laser fibre engraving is the best way to engrave metals bare. Metal and plastic fibres can be marked with laser beams, including aluminium, brass, copper, nickel-plated metals, and stainless steel.

In some cases, however, the laser wavelength will not mark certain materials, including transparent materials; the beam, for example, can pass through fine materials, leaving markings on the engraving table instead. Despite fibre laser systems’ ability to mark organic materials such as wood and clear glass, it is not their best use.

Marks and their types

Fibre laser marking on metal can be done in various ways depending on the type of material to be marked. A laser is used to vaporize materials from objects through engraving. A cone-shaped mark often results from the beam’s shape. By repeating the cycle, the system creates deep engraving that will not wear under harsh environmental conditions.

The material beneath the top layer is usually revealed by ablation. Anodized and powdered metals can all be rubbed.

A heated surface can also be marked. When metals are heated to high temperatures, annealing creates a layer of oxide that leaves a high-contrast mark. As the texture of a material melts, gas bubbles form, which is trapped as it cools and causes a bubbled effect. During polishing, a metal surface is heated rapidly to reverse its colour. A mirror-like finish is achieved as a result—among other metals containing carbon and oxides, anodizing treats steel alloys, iron, and titanium. Plastic is usually marked with foam but can also be used on stainless steel.

Materials to Consider

By changing laser data, such as speed, power, frequency, and focus, stainless steel may be marked using annealing, etching, and polishing procedures. A fibre laser produces more brightness than a CO2 laser with anodized aluminium. It engraves bare aluminium with grey shades, not black. Additionally, aluminium can be oxidized or coloured after deep etching.

The laser creates a wide range of colours when it marks titanium. However, adjusting the frequency can produce different shades of marks.

Best of Both Worlds

Companies with limited budgets or space should consider dual-source systems because of their flexibility and capabilities. When using one at the same time, the other is useless.

Marks ranging from white to grey to black on anodized aluminium

Different marking effects can be achieved when aluminium is removed from its colour or material. The anodized layers can be wholly or partially removed by laser.

A ceramic layer is formed on anodized aluminium (5-30 m thick) to protect the surface. Colouring the porous layer can produce decorative effects. Different results can also be achieved with varying wavelengths of laser (and the subsequent removal of varied material layers).

For instance, anodized aluminium is frequently used in machine construction. The Housings and Covers section contains screws, covers, and other parts.

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