Whether you are new to laser marking or have already had a giant journey in laser marking technologies, it’s a quest for non-stop enhancement of the high-quality and contrasts of laser marks. Laser marking metals is mainly necessary as metals are ubiquitous in noticeably lots the whole thing we contact in each day lives, from digital devices to state-of-the-art scientific equipment.
Laser marked metal
Part with a laser-marked serial number. Courtesy of How To Laser
Laser marking is a non-contact approach to completely marking metals, the place depth of the reduce can be controlled and even automated. Laser marking is handy in that it is well suited with nearly any vector software, like CAD or Illustrator, for marking patterns. As with all machining techniques, there are some vital elements to be viewed when laser marking metals and that’s precisely what we will talk about in this weblog post. Without similar ado, right here are 5 matters to think about when laser marking metals.
1. Material Properties
With all laser marking applications, it is essential to think about what fabric is being marked. Materials have distinct absorption spectra which means they react in another way to specific wavelengths. This should be stored in thinking when identifying what fabric to use with what laser source. The melting factor and the material’s response to warmth need to additionally be considered. The hardness of the fabric must additionally be taken into consideration. For instance, laser marking aluminum will take much less time than laser marking metal on account that it is a great deal of softer steel with decreased melting temperature.
2. Type of the Laser
It is possible to mark metals using both pulsed and continuous-wave lasers. However, pulsed fiber lasers are used extra regularly considering the fact that they can supply a greater depth beam besides overheating the sample. Common sorts of lasers used for laser marking encompass “carbon dioxide, ytterbium-doped fiber, UV, and inexperienced and neodymium vanadate lasers” (from How to Laser).
CO2 lasers are much less used for metallic and greater for woods, glasses, and plastics. Green lasers, again, are much less used for metals and extra so for plastics and glasses. Fiber lasers are commonly used for marking metals and are appropriate for a vast range of them, ranging from metal to copper. Lasers of >50W strength are commonly advocated for marking metals. Fiber lasers can be designed to have greater beam high-quality than lasers of comparable common output power. This beam pleasant controls the beam’s spot size, and consequently the width or the finesse of the laser marking.
3. The Choice of Laser Marking Method
There are a couple of techniques for laser marking metals that produce one-of-a-kind form of marks. The sturdiness and time consideration for every approach are simply some of what wants to be weighed when finding out which approach is most suitable for a precise application. Consider these strategies:
This technique sublimes the metal. The warmth from the laser vaporizes the metal, inflicting it to go immediately from its stable country to gas. In the context of laser marking methods, laser engraving creates very resistant markings, as it creates a very deep mark. For laser engraving, the depth of the reduce tends to vary from 0.0001” to 0.005”. The everlasting marks of laser engraving are very proper in functions the place phase traceability is concerned.
Laser etching is a very speedy procedure that melts the metallic nearly instantaneously. It creates excessive distinction marks. Laser etching is much less everlasting than laser engraving, and though they are similar, etching is commonly a shallower mark—less than 0.0001”—than that for engraving. Since the marks created with etching are shallower, they are additionally appropriate for thinner sheets of steel that require much less permanency of the marks.
This system makes it feasible to create colored markings for unique metals, particularly steel, titanium, and stainless steel. This technique does no longer honestly put off material—rather, it creates a chemical exchange underneath the material’s floor making it best for surfaces that can’t face up to any damage. With annealing, the steel is slowly heated by means of the laser beam altering the lattice shape of the metal. The steel oxidizes and as soon as it cooled modifications the color.
For annealed metals, when incident mild hits the metal’s surface, some of the mild is mirrored off the oxide layer and some is absorbed. The absorbed mild then is both absorbed or mirrored off the oxide layer. The thicker the oxide layer, the darker the coloration the metallic appears.
Laser marking metallic technique of laser annealing
Laser ablation is a way to selectively put off cloth from a strong floor in a managed fashion. This approach can be used for paint elimination or skinny movie removal, which is a a lot faster and greater environmentally-friendly system than that commonly used for skinny movie removal, on the other hand it can additionally be used to savings movies to a surface, no longer simply cast off them.
4. Work Environment
As with any machining operation, it is crucial to make certainly applicable airflow and ventilation/filtration structures are being used. Lasers of course generate heat, and laser marking metals can produce vapors and particles. This makes having a secure work surrounding of utmost importance.
One of the selections to be made is finding out if it makes experience to buy a laser marking setup or to simply have the offerings carried out by way of every other party, and if one is a higher funding than the other. This may want to be based on the range of merchandise that requires marking and/or the frequency of the use of the laser marking setup. The cloth price and time to whole every laser marking ought to additionally be considered.