Laser cutting is a modern and highly efficient metalworking method that enables precise and clean cuts even on the most complex materials. However, despite its advantages, this process is not immune to defects. Understanding their types, causes, and solutions allows for improved product quality and streamlining of production processes.

In this article, we'll look at the main defects of laser cutting, their causes, and how to eliminate them to minimize potential problems and achieve the most accurate and high-quality cuts.

What is laser cutting?

Laser cutting — is a process in which a material is processed using a high-energy laser beam, which heats, melts, or vaporizes the material at the cutting point. This method produces highly precise and clean edges on metals, plastics, and other materials.

Laser cutting is widely used in industry for the production of parts, structural elements, and sheet metal processing. However, despite its precision, laser cutting can introduce various defects that can degrade the product's performance.

The main defects of laser cutting

1. Thermal deformation of the material

Thermal distortion occurs when the material in the cutting zone is heated intensely, which can cause it to change shape. This is especially true for materials with low thermal conductivity or those sensitive to high temperatures, such as aluminum or stainless steel.

Reasons: Incorrect laser beam parameters, high cutting speed, incorrect laser power setting.
Consequences: warping or bending of the material, especially on large sheets, and uneven cutting.

Methods of elimination:

Adjustable laser power depending on thickness and material.
Using a cooling system to prevent overheating.
Applying the correct cutting speed and laser beam focus parameters.

2. Oxidation and carbon deposits

Oxidation And carbon deposits These are common defects that frequently occur during laser cutting, especially when using an oxygen atmosphere. These defects appear as an oxide film or dark spots on the cut edges.

Reasons: Use of oxygen as cutting gas, incorrect gas pressure settings, poor gas quality.
Consequences: deterioration in the appearance of the material, problems with further processing or welding, and a decrease in corrosion resistance.

Methods of elimination:

Using inert gases such as nitrogen for cutting stainless and carbon steels.
Adjusting gas pressure during cutting.
Using post-processing such as polishing or chemical etching to remove carbon deposits.

3. Unevenness on the cutting edges

Unevenness at the cut edges (called "roughness" or "jaggies") can occur if the laser cutting parameters are incorrectly selected. This may be due to insufficient laser power, high cutting speed, or improper focus adjustment.

Reasons: Laser beam instability, poor gas quality, low cutting speed, incorrect laser beam angle.
Consequences: deterioration of the quality of connections, difficulty during installation, increased likelihood of microcracks in uneven areas.

Methods of elimination:

Correct selection of laser beam focus and cutting speed depending on the material and its thickness.
Using high quality gas for cutting.
Regular testing and adjustment of equipment to ensure process stability.

4. Calcination or over-melting of the material

Calcination or excess melting Material melting occurs when the laser beam impinges too strongly on the material, causing it to melt excessively. This can occur when the laser power is too high or the cutting speed is too slow.

Reasons: Incorrect laser power setting, slow laser beam speed, poor material cooling.
Consequences: loss of cutting accuracy, formation of excess molten metal, which leads to difficulties in processing.

Methods of elimination:

Increased cutting speed and optimized laser power for each material type.
Using temperature management technology to minimize material overheating.

5. Cracks and deformations at the edges

Cracks at the cut edges can occur due to internal stress in the material or uneven temperatures during the cutting process. This leads to the formation of microcracks, which can deepen and eventually lead to failure of the part.

Reasons: improper cooling of the material, cutting under high temperature conditions, poor surface preparation.
Consequences: reduction in the strength and durability of the material, increasing the risk of product failure during operation.

Methods of elimination:

Application of preheating or cooling of the material.
Selecting the correct gases and laser power for each type of material.
Carrying out additional heat treatment to relieve internal stress.

How to avoid laser cutting defects?

To minimize the likelihood of defects during laser cutting, it is necessary to follow several key recommendations:

Correct setting of laser parameters. It is important to consider the material type, its thickness and characteristics when choosing laser power, cutting speed and gas pressure.
Use of high-quality consumables. The quality of the gas used for cutting (oxygen, nitrogen, argon) directly affects the quality of the cut and the prevention of defects.
Careful preparation of material. Before cutting, it is important to clean the metal surface from dirt, rust and other foreign particles to avoid the formation of additional defects.
Temperature control. Adjusting the cutting speed and the use of cooling systems will help prevent material overheating and deformation.
Post-processing. If defects such as carbon deposits or oxidation occur, various post-processing methods such as chemical etching or mechanical grinding can be used to improve the appearance and quality of the product.

Conclusion

Laser cutting defects can significantly impact product quality and lead to additional repair costs. Understanding their causes and types allows you to avoid most problems proactively and achieve the best possible laser cutting results. Regular testing and equipment adjustments, as well as using the correct materials and cutting gases, are key to successful and high-quality metal processing.

Using modern technologies and following recommendations for setting up laser systems will help minimize defects and ensure long-term and efficient operation of the equipment.