Fiber lasers are used to carry out laser direct part marking (LDPM) on various metals. From the softer to the hardest metals, it is possible to mark individualized identifiers that takes the forms of barcode, 2D codes, logos and texts.
Our experts at Laserax recommend the use of 2D barcodes for most industrial applications, particularly DataMatrix Codes (DMCs) for the following reasons:
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There are three laser marking mechanisms commonly used on metals. There is laser engraving, laser etching and laser annealing.
For aluminum and many other metals, it is customary to use laser engraving or laser etching to uniquely identify products. It is possible to create markings such as the one illustrated in the image above.
For stainless steel, carbon steel, chrome, other ferrous metals and titanium, another laser marking process exists: laser annealing. Both laser engraving and laser annealing will be discussed further below.
You can also get more information on the differences between laser engraving, laser etching and other laser marking processes in this other blog post.
Laser engraving involves high power in very little time and creates crevices in the material. Shallow crevices (as shown in Figure b in the image above) reflect light beams in all directions, resulting in a pale marking. Deep crevices (as shown in Figure c ) reflect much less light, resulting in a darker mark. Laser etching is very similar except that the markings end up being deeper.
For more information on the impact of laser marking on the surface of aluminum parts and the optical mechanism behind the change in colour for laser marking, consult Laserax’s white paper, entitled: Surface Analysis Study of Laser Marking of Aluminum published at ICSOBA 2016 conference.
Here is an example of an automated laser marking machine we delivered to one of our customers in the aluminum industry in our blog post, Automation of Laser Marking System for Pick-and-place Robots.
Laser annealing is completely different from laser engraving and laser etching. It involves relatively low power over longer periods of times. No materials are removed; however, the color of the stainless steel surface is changed. By modulating the laser parameters, we can get a rather wide array of colors, as shown in the picture above.
Laser annealing is often used for the identification of medical instruments. It is especially popular since regulations in the US requires Unique Identifications (UIDs) of all medical instruments.
Another typical application is the direct part marking of automotive parts that are subjected to salty environments at high temperatures.
Permanent part marking ranges from logos and serial numbers to barcodes and certification marks. It’s a critical step in manufacturing as a way to maintain control over quality, comply with regulatory requirements, and ensure the traceability of products.
For industrial laser marking, high-speed lasers are essential to meet tight production schedules while maintaining high-quality standards. But with so many options available, choosing can be confusing. After all, you want a machine that not only performs at high speeds, but that is also cost effective.
Laser marking is the first choice when manufacturers need to improve their traceability capabilities. Fiber laser technology is recognized as the best option when it comes to permanent markings, high-contrast codes, post-process resistance, and ease of integration.
