Laser Marking How it works and types
Laser is the best technology for metal marking, where it can achieve diverse results. It has no more efficient process than with lasers at an industrial level; this means there are fewer steps in production times and increased quality control over what you’re engraving or cutting out of your product – all without touching anything!
Most laser marking machines focus a high-powered beam of light onto a surface, which can be controlled to leave an extremely fine mark. When the power is increased enough, the material begins to melt and vaporize, creating a very small crater or “pit” in the top layer of the material. The lasers used for Lasermarkierung auf Metallentypically operate near-infrared wavelengths (1064nm) or ultraviolet wavelengths (355nm).
At 355nm wavelength, metal etching can produce deep marks that will last up to 99% longer than traditional chemical etching methods such as ferric chloride. It also does not create fumes like ferric chloride, and it requires less equipment.
There are many choices when choosing a laser for this process: Nd: YAG, CO2, Fiber, Diode.
Nd: YAG lasers are one of the best choices for marking metals. They typically have a long life span with very few spare parts required. Nd: YAG lasers also have high peak power ratings for deep mark penetration and long-range precision delivery. Their pulse frequency can be varied between 10-20kHz, which is better suited to marking metals than other types of laser systems. Their run-time per charge is excellent for on-demand marking applications with limited machine downtime due to recharging requirements or battery life limitations.
CO2 lasers are mainly known as “sheet metal” marking systems – although some manufacturers offer more compact designs that are better suited to marking metal surfaces. CO2 lasers have a very high degree of focus. However, they lack the power required for deep mark penetration and long-range delivery. This makes them a good choice for sheet metal marking but a poor choice for metals that require deeper mark penetration, such as engine blocks or gear sets.
Fiber Laser Marking Systems are gaining market share in the “high value” marking market – where marking costs must be kept low due to their complexity and cost structure. Fiber laser systems can also provide excellent results on flat surfaces such as work plates and glass testers, which make them an attractive addition to any production line or lab testing environment. Their main drawback is their limited ability to deliver deep marks on cylindrical components because of the beam profile.
Diode laser marking systems have a spot size so large that their ability to deliver deep marks is minimal compared to other types of metal marking lasers. They can be used for “marking” but typically will not provide the same quality results as Nd: YAG or CO2 lasers due to their lack of power and focusing capability. Ultra-compact Diode lasers are also available. However, they usually require specific mounting hardware (and do not fit in standard laser holders).