Copper is a metal that is used for several purposes. It is much cheaper than silver or gold and, at times, the only economical option that you might have. Among its several uses, one is making signs and plates using copper, but is it possible to engrave those signs according to your liking?
Copper can be engraved using a laser. However, copper is a highly reflective metal and absorbs very little light. It is not as easy to carve as gold or silver. Carbon dioxide laser engraving does not work for copper because the copper ends up reflecting it all.
To engrave copper, you might need a fiber laser. Fiber lasers have a shorter wavelength than carbon dioxide lasers, so they can penetrate the copper and leave their mark. There are many ways to laser engrave copper, but you need to adopt methods that work with the unique properties of copper.
If you want to learn about these techniques in greater detail, keep reading ahead!
What Is Laser Engraving?
Before we explain the process of engraving copper, having a bit of context is crucial. Laser engraving is the process whereby a laser is used to leave marks on a material.
This is done by the laser beams vaporizing the material into fumes and removing layers from the surface of the material you intend to engrave on. The intense heat that the laser provides aids the vaporization process, and deep, permanent marks are etched on the object’s surface.
To see this process for yourself, watch this video
Why Is Copper Hard To Engrave?
Copper is a great conductor of heat and electricity but is also highly reflective. Pure copper reflects > 95% of near-IR radiation (~ 1 µm wavelength) in its solid state. The low absorption of copper means that infrared rays are not fully absorbed, making it challenging to engrave. The challenge is even more significant when the copper is in its solid state.
Why Does Carbon dioxide Laser Engraving Not Work On Copper?
Carbon dioxide lasers use this gas to remove thin layers from the object’s surface. This method is popular, but the Co2 laser generally has a high wavelength of 10.6 µm. This makes it harder for Co2 to penetrate the surface of the copper.
How Do We Engrave Copper?
Reflective metals such as copper are easier to engrave in their molten state because, in their molten state, they have lower reflectivity and can be easily penetrated. One way to engrave copper is to melt it first.
But the standard practice that suits copper the most is engraving it using fiber lasers. Fiber lasers have a wavelength of 1.07 µm; they have a diameter that is 1/10th of the diameter of a Co2 laser beam. They provide higher density, and this high density melts the copper easily, making it less challenging to penetrate. Once this is done, the copper can be engraved.
The Bottom Line
Laser engraving copper is very much possible, but you must keep in mind the highly reflective nature of copper and engrave it using the correct technique and the proper equipment. If you have that set, then you’re good to go!
