What is Laser Marking?
Laser marking is an industrial process used to mark logos, text, graphics, barcodes, such as data matrix or QR codes, and alphanumeric serial numbers onto a surface. Laser marking uses the heat of the laser to alter the surface and generate a permanent mark. The most common types of laser marking are laser etching, laser engraving, and laser annealing.
Key applications for laser marking include part identification in the automotive industry and ingot labeling in the metallurgy industry. Due to product liability and traceability concerns, the demand for laser marking is rising in these industries.
In comparison with traditional direct part marking (DPM) methods, such as inkjet marking, dot peening, and electro-chemical etching, laser marking offers many benefits:
- Laser marking does not use ink, require consumables, or need pretreatment
- Laser marking generates high-quality, high-contrast, and ultra-precise marks, such as logos, text, graphics, linear barcodes, and 2D codes
- Laser marking can be applied to any parts regardless of their material and geometry
- Laser marking can be integrated into an assembly line
- Laser marking does not impact the production rate, resulting in high performance, speed, and throughput
Types of laser marking
Contrary to traditional direct part marking that uses ink or consumables to identify parts, laser direct part marking uses the laser to mark information directly on a part.
Laser marking is a generic term that includes laser etching, laser engraving, and laser annealing.
Laser etching uses high-intensity pulsed lasers to melt the surface of the material. The melted material expands and forms crevices and bumps. Dark and light areas appear on the surface.
Because laser etching modifies the roughness of the surface, it changes the way light is reflected on the marked area. The result obtained with laser etching is high-contrast marks that can be read either with scanners or by human operators
Laser engraving involves high laser power during a very short time applied on a localized area. Laser engraving happens from the vaporization of the material, which generates the formation of reliefs on the surface.
By controlling the laser parameters, laser engraving generates pale to dark areas. The result obtained is high-contrast marks that can withstand shotblasting post-treatment, thanks to patent-pending Laserax’s unique shotblast-resistant marking process
Laser annealing involves low laser power over a longer period of time. Laser annealing occurs when an oxide layer is created by heating ferrous metals, such as steel, stainless steel, and titanium. The chemical modification of the material changes the color of the surface. Laser annealing is feasible on ferrous metals only, which means that aluminum and non-ferrous metals cannot be annealed.
Laser annealing is recommended for parts that are subjected to large fluctuations in temperature, a high degree of humidity or a high exposure to salt, such as automotive parts because it prevents the formation of nooks and crannies that may bait in corrosion.
Laser marking depends on both the material properties and the laser parameters. The laser parameters, such as the wavelength and laser power, are optimized to match the material properties, such as the absorption threshold, in order to obtain the desired marking quality. The material absorption, which impacts the marking quality, depends on the wavelength of the laser and the marking time depends on the laser power.
The efficiency of the laser marking process can be defined by the balance between the marking quality and marking time. These two elements play a role in the selection of the optimal laser marking solution.
Thanks to the very nature of lasers, identifiers can be permanently embedded on the most difficult surfaces, regardless of the type of materials.
Metals are the preferred materials for laser etching, engraving, and annealing. Because of their unique properties, such as durability, robustness, or malleability, metals are widely used in the automotive, manufacturing and other industries. Whether the metal is steel, stainless steel, aluminum, magnesium, or any type of alloy, the laser parameters (power and wavelength) are optimized to match the metal properties in order to obtain contrasted and resistant marking of high quality.
Plastics are widely used in the manufacturing industry. Their ability to be produced and shaped at low cost, in addition to their unique properties, explain why they are present everywhere in our daily life. Fiber lasers can be used to generate high-contrast marking on plastic surfaces. The identifier generally appears white or gray regardless of the base color of the irradiated plastic. Marking on plastic can be done at high speeds. Most plastics are quite easy to mark with a laser. A proper fume extraction system is required to move the fumes away from the work area.
Rubber is an important material used in the automotive industry. Fiber lasers can be used to generate high-contrast marking on rubber surfaces. The identifier generally appears white or gray regardless of the base color of the irradiated rubber. Marking on rubber can be done quickly. A proper fume extraction system is required to move the fumes away from the working area.
Fiber lasers are Laserax’s preferred laser marking solution because they offer several benefits:
- They are wavelength flexible, which enables direct part marking on a variety of materials, such as metal—ferrous and non-ferrous, plastics, or rubber.
- They are energy efficient because of their low level of electricity consumption and small heat management requirements.
- They are more compact than other types of lasers—gas or solid-state—of equivalent optical power.
- They have a lower cost of ownership than other types of lasers.
- They require low maintenance.
- They have a mean time between failure (MTBF) of up to 100,000 hours, which represents several years of production
- They are very stable and reliable, which makes them the most suited laser marking solution for industrial environments.
Laser Marking Application Videos
Aluminum Die Casting Laser Direct Part Marking
Lasers can be used to permanently identify die castings. The identifier often takes the form of a Data Matrix Code such as the one shown in this video. 2D Codes can be read by a scanner and are often accompanied by a Human Readable Interpretation (HRI).
Laser Engraving on Metal
Laser engraving occurs when a large quantity of energy is transferred in a very short amount of time to a targeted surface. The results is the localized vaporization of the material being engraved. It creates wavy patterns or deep crevices; these patterns generate the pale and dark areas we see here.
Laser Marking on Lead
Laserax’s Laser markers can be used on a wide variety of metals. From stainless steel and titanium to aluminum and magnesium. In this case, a soft metallic sample is being labeled with extensive information. In this video, watch one of our lasers identifying a lead sample.
Laser Labeling on Aluminum Ingot
Aluminum ingots such as the one shown here, are known for their rough surfaces. Some direct part marking technology might have difficulty with such surface roughness, but Laserax’s laser marker easily vanquish this challenge.
Laser Marking on Plastics
Polyethylene is another material that can benefit from a nice laser mark. Laserax has developed laser marking solutions that are equipped with the necessary fume and dust management systems that will make marking on plastics a great alternative to other technologies.
Laserax’s Laser Solutions
INLINE LASER MARKING SOLUTIONS
Laserax has developed complete turnkey laser marking solutions that are adapted to the specific needs of today’s manufacturers. These complete laser marking machines are used to permanently identify metallic products with unique tracking codes that will provide traceability to the entire value chain.
OEM LASER SYSTEMS
The same lasers used in Laserax’s laser marking solutions for over ten years are now available to integrators, machine builders and other partners for use as OEM components.