No matter how much or how little experience you have with laser marking technologies, it is a quest for continuous improvement of the quality and contrast of laser marks. Since metals are ubiquitous, from electronic gadgets to advanced medical devices, laser marking metals is particularly important.
Material Properties
In all laser marking applications, the material to be marked should be taken into consideration. A material’s absorption spectrum determines how it reacts to light. When selecting which laser source to use with which material, keep this in mind.
Characteristics of the Laser
Metals can be laser marked with both pulsed lasers and CW lasers. The pulsed fiber laser is more commonly used due to its ability to deliver a higher intensity beam without heating the sample. In addition to carbon dioxide lasers, ytterbium-doped fiber lasers, UV lasers, and green and neodymium vanadate lasers are common types of lasers used for laser marking (How to Laser).
Choosing the Right Laser Marking Method
Metals can be marked with lasers in different ways that produce different types of marks. When deciding which method is most suitable for a particular application, it is important to weigh factors such as durability and time. Following are some examples:
Laser Engraving
The metal is sublimated in this way. Metal goes directly from its solid state to a gas due to the heat from the laser. In the context of laser marking methods, laser engraving creates very durable marks, since they create a very deep print. Typically, laser engraving cuts between 0.0001″ and 0.005″ deep. Laser engraving produces permanent marks that are highly desirable for parts traceability applications.
Laser Etching
Laser etching melts metal almost instantly because it is a very fast process. The marks are very contrasty. Laser etching is more temporary than laser engraving, though the marks left by etching are typically shallower (less than 0.0001 inches) than those of engraving. The shallower depth of the marks created by etching makes them suitable for thinner metal sheets that require less permanent markings.
Laser Annealing
Metals such as steel, titanium, and stainless steel can be marked with colored markings using this method. Methods like this do not actually remove material; they create a chemical change under the surface of the material, making them ideal for surfaces that are fragile or can’t withstand any damage. During an annealing process, the lattice structure of the metal changes as a result of the laser beam slowly heating it.
Laser Ablation
By using a laser, you can selectively remove material from a solid surface in a controlled way. With this method, it is possible to remove paint or thin films more quickly and more environmentally friendly than using traditional methods The process is typically used to remove thin films, but it can also be used to deposit films on a surface, not just remove them.
Work Environment
The use of proper airflow and ventilation/filtration systems is crucial to any machining operation. Metals can be marked with lasers that produce vapors and particles as well as heat. Keeping a safe working environment is therefore imperative.
Cost
You will have to decide if it is worth investing in a laser marking setup or having the work performed by a third party, and which is the better decision. A laser marking setup might need to be changed depending on the number of products that need to be marked and/or the frequency of use. It is also important to consider the cost of material and the time needed to mark each product.
Conclusion
Keeping these things in mind is essential when laser marking metal. The laser marking process can be explored further on this blog in various articles, some of which are listed below.
Rehan is a student of Masters at the University of Birmingham. He loves writing about business, finance, technology, and life. He believes that sharing knowledge with the public is the best thing that one can do for the world and humanity.