Introduction
In the field of material processing, laser technology offers a wide range of advanced applications. Two of the most commonly used techniques are laser marking and laser welding. Although both use a laser beam to interact with materials, their purposes and modes of operation are significantly different.
Laser marking
Laser marking is a process mainly used to create permanent marks on a material. This may include barcodes, serial numbers, logos, text or complex designs. Marking occurs through the interaction of the laser beam with the surface of the material, causing a chemical or physical change. There are various types of laser marking, including:
- Engraving: The laser removes part of the material to create a permanent, deep mark.
- Ablation: Removal of a surface layer without damaging the underlying material.
- Blackening: The laser heats the material to the point of causing a colour change.
- Skimming: Used mainly on plastics, the laser creates microscopic bubbles that reflect light and appear white.
Laser marking is highly valued for its precision and durability, making it ideal for the automotive, medical and consumer goods industries (CNCSourced) (Keyence).
Laser Welding
Laser welding, on the other hand, is a process used to join two materials together. This is done by focusing a powerful laser beam on a precise point of the materials to be joined, which are melted and then solidified to create a joint. Laser welding is commonly used for metals and certain types of plastics. There are several laser welding methods, including:
- Deep penetration welding: The laser penetrates deeply into the material to create a strong and durable weld.
- Conduction welding: A less powerful laser beam is used that heats only the surface of the materials, creating a shallower joint.
- Spot welding: Ideal for applications requiring small joints on thin materials.
Laser welding offers a high level of precision and control, making it essential for industrial applications such as electronics manufacturing, machine building and aerospace (Manufacturing on Demand) (WOOCNC).
Comparison of Marking and Welding
Although both technologies use lasers, their applications differ significantly:
- Objective: Laser marking is used to identify and decorate, while laser welding is used to join materials.
- Laser intensity: Marking requires less energy than welding, because it doesn’t need to penetrate the entire thickness of the material.
- Materials: Both technologies can work on a variety of materials; however, laser welding demands more power for thicker or harder materials.
- Precision and control: Both processes are highly accurate, but laser welding requires more stringent control to ensure strong joints without deformation (Keyence) (WOOCNC).
Best Marking and Welding Lasers on the Market
The most advanced marking lasers available today include fibre, CO2 and UV lasers. Of the fibre lasers, the MOPA is renowned for its versatility and precision. For laser welding, fibre and diode lasers are the most widely used due to their ability to generate strong and durable joints. Brands such as LASIT, Trumpf and Epilog are known for the quality of their machines, ensuring optimal results across various industrial applications (CNCSourced) (WOOCNC) (Proleantech).
Conclusion
Understanding the differences between laser marking and laser welding is crucial in selecting the technology that best fits your needs. Marking is ideal for traceability and decoration, while welding is perfect for joining materials. Both technologies, each with their specific applications, improve efficiency and quality in industrial manufacturing.