As the name suggests, reflective metal is a metal that can reflect the wavelength directed to it. Examples of these metals are copper, brass and bronze. Aluminum, gold and silver have the highest reflectivity, with the latter reflecting about 95% of visible light.
Aluminum Brass Bronze
This poses obvious problems for the laser cutting process involving heat and light laser beams. Below we explain how to use a fiber laser to cut reflective metals.
Why is there a problem with laser cutting reflective metal?
As mentioned above, reflective metal can redirect many things against it back to the light source. This is called “tempering”, and if the laser of the laser-based cutting machine itself eventually damages the equipment, it can cause serious damage.
Some laser machines can cost thousands of pounds and have expensive replacement parts, so this obviously needs to be avoided. Gas laser cutting is the most common laser cutting method. It was established in 1964 and is still a common method today.
Nevertheless, it may be the most troublesome when cutting any other metal that will reflect during cutting. This is because it uses beams and mirrors so that the beam can be reflected back to the laser itself in many places.
Although some people try to solve this problem by placing a non-reflective coating on the metal, the molten metal produced during laser cutting is itself reflective. This means that no matter how many non-reflective coatings you use, this will also damage the laser. Gas lasers especially have to fight yellow metals such as copper or brass.
However, this is not to say that gas lasers cannot be used with reflective metals at all. Although there is still a risk of damage, steps can be taken to successfully complete the process. Generally, modern lasers have fail-safe features by detecting when too much heat is reflected back to the laser and then turning it off.
What is the best solution for cutting reflective metal?
Despite these advancements in gas laser technology, it is still not the most effective method, and you are still at risk of damage. Fiber laser cutting is the latest development of laser-based cutting technology, and it is a solution to effectively deal with reflective metals.
This type of technology does not use mirrors, gases or precision lenses, but uses fiber optic cables. This means that the reflective properties of metal will not cause damage to fiber lasers like gas or crystal lasers.
However, it must be noted that fiber lasers are only effective for metals with a thickness of less than 5mm. Fiber lasers can still be used to cut any metal higher than this height, but the speed becomes slower and the cutting quality decreases. For these situations, waterjet laser cutting is usually recommended as the recommended solution.
Reflective metals are used in many industries around the world, such as electronics, automotive, aerospace and semiconductor industries, so it is important to cut reliably and keep high quality in mind.