The quality and contrast of the laser marks can always be improved, regardless of how familiar you are with laser marking or how much experience you have. In medical equipment or electronic devices, we touch metal almost every day, which is why marking metal with lasers is so important.
With a laser, marking metals permanently is a non-contact, automated, depth-controlled procedure. The use of vector software, such as Illustrator or CAD, is very useful for marking metal patterns. When laser marking metal, we need to consider a few important factors. Below are five factors we need to consider.
When laser marking, the material should be considered. Therefore, different materials absorb light differently, which is why they react differently to the light at different wavelengths.
When choosing materials for laser sources, this should be considered. As well as the melting point, you should look at how the material reacts to heat. It is also important to consider how hard the material is. Despite its lower melting point, aluminum is a softer metal than steel, making laser marking easier.
2. The laser’s characteristics
Both continuous wave and pulsed lasers can be used to mark metal. The intensity of a pulsed fiber laser beam can be higher than that of a pulsed fiber laser without overheating your sample. (How to Laser) The most common lasers used for laser marking are carbon dioxide, ytterbium-doped fiber, UV, green, and neodymium vanadium lasers.
Typically, the CO2 laser is used with wood, glass, or plastic rather than metal. Plastics and glasses are generally processed with green lasers rather than metals. Steel, aluminum, and copper are among the metals that can be marked with fiber lasers. It is usually necessary to use lasers that have a power of at least 50 watts in order to mark metals. A fiber laser produces a better beam than a laser of similar power. In laser marking, the size of the spot is determined by the beam quality.
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3. Selecting the Best Laser Marking Method
Several different laser marking techniques are available for marking metals. When choosing a method for a particular application, durability and time should be taken into account. For example:
Engraving is done with a laser
Sublimation is the process of turning a metal into a gas. The heat generated by the laser converts solid metal directly into gas. In contrast to laser marking, laser engraving leaves deep marks that are very resistant. Engraving with a laser usually cuts between 0.001″ and 0.005″ thick. Laser engraving provides permanent markings that can be particularly useful in applications requiring part tracking.
Efficient use of lasers for etching
When lasers are used to etch metal, it melts almost instantly. The resulting marks are highly contrasted. Laser etching typically leaves a smaller mark than laser engraving, less than 0.0001″. It is also suitable for less permanent markings since etching can be used for thinner metal sheets.
4. Anodizing with lasers
Colored markings can be applied to specific metals, including steel, titanium, and stainless steel. Rather than removing material, this method creates a chemical reaction beneath the surface, making it ideal for surfaces that cannot withstand damage.
By slowly heating metal with a laser beam, its lattice structure is altered. This causes the metal to oxidize and change colors upon cooling. Oxides reflect a portion of incident light and are absorbed by metals annealed at high temperatures. Light is reflected back into space after being absorbed by the oxide layer. Darker metallic colors result from a thicker oxide layer.
Investing in a laser marking setup or having the work done by another party is a matter of deciding which is a better investment. The length of time a laser marking setup takes to set up will depend on how much product needs to be marked as well as how frequently it is used. It is also important to consider how long it takes to mark the product in addition to the cost.