Laser welding is a precise process using high-energy laser beams to fuse metals. It offers excellent advantages over traditional welding – rapid welding and producing clean welds with minimal defects. While laser welding equipment is generally more expensive, its operational costs are lower, as it does not require additional filler material.
However, this article focuses on whether a laser welding machine suits metal cutting applications. We already mentioned that the device offers excellent metal joining capabilities. Can it cut metals? Find out in this article.
What is Laser Weld?
Laser weld metal is a high-precision process that uses a concentrated laser beam to join or fuse metals and other compatible materials. It is a non-contact process that uses a focused heat source in the form of lasers to melt materials, fusing them as they cool down.
This welding method is highly versatile and suits the welding of various materials. While welding is more commonly associated with metals, this process is compatible with thermoplastics, glasses, and composites.
Metal laser welding offers high accuracy and speed. The high speed involved in the process makes it an excellent choice for thin and complex joints. It also produces materials with low thermal distortions and clean finishes, making it an excellent choice across various industries.
Can a Laser Welder Cut Metal?
Yes, a laser welder can cut metal. Although laser welders are purposely built for joining materials rather than cutting them, some advanced high-power laser welding machines combine cutting capabilities. While cutting is not their primary function, the focused heat these laser welders generate to bond metals can be enhanced for cutting.
However, you may need to adjust the laser setup when using this device for cutting. Laser cutters operate with a broader beam and often use gasses like oxygen or nitrogen to assist in the cutting process. While laser welding machines might be able to cut some metals and specific materials, they are less effective and efficient than machines specially designed for cutting.
What Laser Machine Can Cut Metal?
When cutting metals is the goal, a laser cutting machine is more advisable than a laser welder. There are three different types of laser cutters designed for cutting metal. They include the following.
CO₂ Lasers
A CO₂ laser is the most common laser cutting equipment. The laser source is from running electricity in a tube-filled gas mixture. The gas in the tube is predominantly CO₂ and a mixture of inert gasses, particularly nitrogen and helium. These lasers can operate in a continuous or pulsed mode under low current or high voltage to excite the gas molecule.
However, the gas helps blow away the molten material and debris, enhancing the cutting speed and quality. CO₂ lasers are commonly used for cutting metals and non-metals. They operate at high power and feature good laser beams for fast cutting capabilities, though this cutting efficiency drops when cutting thick or reflective metals like copper.
Fiber Lasers
Fiber lasers are a relatively more recent laser type. However, they generate more power than CO₂ lasers, offering better cutting capabilities with increased efficiency and quality yet requiring low maintenance. The laser beams in fiber lasers are created when the fiber absorbs raw light from the pump laser diodes.
The mode of operation involves using optical fiber doped with a rare-earth element as the gain medium. However, the laser features a shorter wavelength, which makes it more suitable for metal cutting. Therefore, fiber lasers are highly efficient for cutting reflective materials like aluminum, brass, copper, and stainless steel while offering cleaner cuts and faster processing times.
ND-YAG (Neodymium-doped Yttrium Aluminum Garnet) Lasers
ND-YAG lasers are solid lasers for specific applications because they offer increased stability and durability. They use a crystal as a laser medium and generate lasers that can produce near-infrared wavelengths. This laser type is suitable for cutting thin sheet metals and non-metals. Although its power is lower than CO₂ laser and fiber laser cutting, it still offers some refined and high-precision metal cutting applications.
What Materials Can and Can’t Be Cut by Laser
Laser cutting can cut a wide range of materials. It is essential to note some of each material’s properties, as some require extra caution when cutting. Although lasers can cut almost anything, some materials can’t be cut by laser. Some of the materials that can be cut and materials that can’t be cut by laser are listed below;
Materials Lasers Can Cut
Laser cutters are suitable for cutting various materials. Below, we examine the common materials these high-focused light beams can cut.
- Metals: Laser cutters are suitable for cutting various metals, ranging from mild steel to stainless steel, copper, aluminum, and other non-ferrous metals. However, we must mention that materials with high reflective metal qualities, like aluminum, are more challenging to cut. Therefore, you should use fiber lasers for such applications. Also, laser cutters are better suited for cutting thin metal sheets and plates up to 30 mm, depending on the machine’s sophistication and the operator’s expertise.
- Wood: Laser cutting devices are more palatable for cutting different types of wood. However, it is important to be aware of the amount of oil or resin present in such wood, as it may pose a threat of catching fire.
- Plastics: Lasers are suitable for cutting various plastics, including thermoplastics, thermosets, synthetic polymers, and other resins. The devices are even more compatible with cutting softer materials like plastics, wood, and paper, producing cleaner edges as though they were polished.
- Paper and Cardboard: Lasers are also suitable for cutting paper and cardboard. Many sophisticated wedding invitations are products of laser cutting services.
- Glass: Cutting glass might seem more challenging because of its fragile and reflective properties. However, laser cutters, especially fiber lasers, can cut glass.
Materials Lasers Can’t Cut
While lasers offer vast cutting abilities, some materials are more challenging to cut, and it may be unadvisable to use them on them. Let’s briefly go over these materials.
- Highly Reflective and Reactive Metals: These include metals and alloys like copper, brass, titanium, galvanized steel, and some painted metals. Highly reflective metals absorb the light beam’s energy, resulting in potential overheating. On the other hand, coated metals are often more reactive and could generate harmful fumes.
- Specific Plastics: While laser cutting is compatible with various plastics, it is discouraged when cutting PVC, polycarbonate, ABS, and HDPE. For example, PVC may release acids and toxic fumes that harm the machine and operators. On the other hand, using lasers to cut polycarbonate may result in discoloration, especially when it is greater than 1mm. Laser beams often vaporize the material when cutting ABS and HDPE, leaving a messy and unclean cut.
Conclusion
We have emphasized that a laser welder machine is excellent for joining metals. However, the device may be adjusted to offer metal cutting functions, especially for thin metals, plastic, and wood. When using this device for cutting, you need to optimize its power settings to suit this function. Still, if your primary goal is cutting metal, consider getting a laser cutting machine rather than a welding device.
