Laser cutting is a popular metal fabrication technology. It utilizes a high-powered, highly focused laser beam to cut the workpiece (material). Modern laser cutters utilize CNC technology, which enhances their precision. Interestingly, there are different types of laser cutting. Each method differs from the others in many aspects.
Some of them are ideal for cutting metals, while others are suitable for non-metals. Additionally, laser cutting methods differ in terms of their cost and pricing. Understanding laser-based cutting is essential, especially if you’re in the metal fabrication business. This article will discuss all the ins and outs of those laser cutting methods.
Basics of Laser Cutting Technology
In a previous article, I discussed the basics of laser cutting technology and its working principles. If you’re a newbie, I highly recommend reading that article first. It will help you understand laser types more easily. Let’s have a brief overview of this technology.
Laser cutting is an advanced technology that utilizes high-energy, highly focused laser beams. These laser beams are aimed at the desired spot. As these lasers have very high energy, they can easily melt the metal or material. In this way, these lasers effectively create cuts in the material.
In the past, laser cutting was a more manual process. The operator had to use the laser head and direct the laser at the materials. However, the modern laser cutting machines come with CNC systems. These machines use computerized instructions fed by operators to cut the materials. Their laser head moves according to the direction of the automated system.
Due to the involvement of CNC, laser cutting has become a contactless process. You don’t need to hold the laser head or worry about workpiece alignment. The laser machines are so advanced that they take care of everything. All you need to do is feed the right computerized or G-coded instructions. The laser head will move and cut the material.
Types of Laser Cutting
As I mentioned earlier, cutting methods differ in many aspects. These include their speed, cost, and compatibility with the material, among other factors. In the section below, we will discuss all popular types of laser cutting. So, let’s dig in!
1- CO₂ Laser Cutting
This laser-based cutting method is very popular among small and medium-sized businesses. It uses a mixture of different gases for its operations. The mixture contains carbon dioxide (CO₂), nitrogen, and helium. Additionally, some assisting gases, such as nitrogen, are also used to clean the cutting area.
These assist gases also blow away the debris that results from cutting. This method needs electrical energy for its operation. This energy excites the mixture of gases. As a result, a high-power laser beam is produced. However, this beam is not very focused or concentrated. This laser, when under the laser head, faces multiple mirrors and lenses.
These lenses make these lasers more focused and concentrated. As a result, the laser beam goes to the desired spot and melts the material surface. The energy of these beams is so high that it can even evaporate the materials. The CO₂ laser cutting method is ideal for non-metallic materials, such as wood, leather, glass, and plastics.
If you use it to cut metals or reflective materials, its effectiveness and efficiency will decrease to a large extent. Here is a table showing the pros and cons of CO₂ laser cutting:
| Pros | Cons |
| High precision, | Not for thick/reflective metals |
| Works on many non-metals. | Slower on metals |
| Great for engraving | Bulky machine size |
| Smooth, clean cuts. | Needs frequent maintenance |
| Lower cost than fiber lasers, | Higher power use |
2- Fiber Laser Cutting
The fiber laser cutting is a more advanced and superior option than CO₂ laser cutting. It does not use a mixture of different gases to produce lasers. Instead, it involves amplifying light to create the laser. First, energy is provided to the material (fiber). This addition of energy in fibers excites the atoms of these materials.
This excitation of atoms releases energy in the form of photons. Interestingly, these photons are not motionless but bounce back inside the laser machines. Their movement or collision of photons further excites other atoms. This results in the stimulated emission of energy. As machines consist of two mirrors, where photons strike randomly.
One mirror is partially removed, and the energy, in the form of a laser beam, escapes from the machine. This laser beam is then directed to the desired spot on the material. As this laser has very high energy, it melts and cuts the materials. Unlike CO₂ laser cutting, this method can easily cut metals and reflective materials.
The laser has excellent cutting strength, allowing it to cut through robust materials. These include stainless steel, aluminum, brass, and others. The technology is particularly effective for precision components like SMT stencils. However, it can be slightly slower when cutting non-metals, such as wood or glass. The initial cost of fiber laser cutting is very high, which is a drawback. However, I still consider this method more cost-effective.
Here is a table showing the pros and cons of fiber laser cutting:
| Pros | Cons |
| Fast and accurate metal cutting, | Not good for non-metals |
| Can cut reflective metals. | Higher machine cost |
| Low maintenance, | Needs a trained operator |
| Uses less electricity. | Setup and learning take time |
| Long laser life, | Not ideal for small or hobby projects |
3- Crystal Laser Cutting
This laser cutting method is more powerful but has less longevity than fiber or CO2 laser cutting. It utilizes solid-state crystals to generate the laser beams. Those common crystals include:
- Nd: YVO (Neodymium-doped Yttrium Orthovanadate)
- Nd: YAG (Neodymium-doped Yttrium Aluminum Garnet)
This higher energy is provided to these crystals. As a result, the atoms inside these crystals absorb the energy. As a result, electrons of these atoms go into a higher energy state. When these electrons come back, they release a large amount of energy in the form of photons.
These photons collide with mirrors inside the laser tube and bounce back repeatedly. As a result, they further excite other electrons, which then release energy in the form of photons. This chain reaction continues to generate more photons, resulting in higher-energy laser beams. This laser beam is then directed at the material, cutting it.
Interestingly, this cutting method provides a high beam with higher power density. Therefore, it can cut through the strongest materials, such as metals and ceramics. Crystal laser cutting machines are less durable and have a shorter lifespan than fiber and CO2 laser methods. Here is a table showing their prominent advantages and disadvantages:
| Pros | Cons |
| Very precise cutting, | Shorter lifespan |
| Cuts hard materials, | High cost |
| Great for fine details, | Heat/humidity sensitive |
| High power in a small size, | Complex setup |
| Low heat damage in pulsed mode, | Less energy efficient |
4- Direct Diode Laser Cutting
This type of laser cutting uses a tiny component known as a laser diode. It is a semiconductor and helps produce high-powered laser beams efficiently. First, the current flows into these diodes. It provides energy to the atoms of diodes. As a result, electrons of those atoms absorb energy and jump to a higher energy state.
Upon returning to a lower energy state, they release energy in the form of photons. These photons further cause stimulated energy emission by exciting other atoms. As a result, high-powered laser beams are produced. Interestingly, the laser diodes used have one mirror on one side. This partial opening of the mirror allows the laser to escape.
Once the lasers escape, they are directed at the material and cut it effectively. This type of laser cutting is suitable for cutting thin material. However, it won’t cut if the material is too thick or dense. What I like about this cutting method is that its energy consumption is very low. Its usage is common in laser marking, soldering, and surface texturing.
Here is a table showing the pros and cons of direct diode laser cutting:
| Pros | Cons |
| High energy efficiency, | Not ideal for thick metals |
| Compact and lightweight, | Lower power output |
| Low maintenance, | Limited material range |
| Fast for thin materials, | Weaker beam quality |
| Lower operating costs, | Shallow cutting depth |
Types of Laser Cutting Based on the Cutting Method
In the preceding section, I discussed various types of laser cutting. Those types differ from each other in terms of laser source. For example, in CO2 laser cutting, a mixture of different gases is the laser source. Similarly, the fiber laser cutting uses optical fiber as the source of the laser.
Crystals and DDL utilize solid-state crystals and tiny diodes to generate lasers, respectively. Right? However, some types of laser cutting are based on the method used to cut the material. For example, some laser cutting methods utilize heat to melt the material, enabling precise cutting. On the flip side, other laser types do not melt the materials.
Instead, they vaporize the targeted spot to cut the material. These laser cutting methods utilize the aforementioned laser types. Here is a table showing those types of laser cutting based on how they cut material:
| Laser Cutting Method | How each method cuts the material or workpiece | Common Laser Types Used |
| Fusion Laser Cutting | Melts material; molten metal is blown away by gas | Fiber Laser, CO₂ Laser |
| Vaporization Laser Cutting | Vaporizes material directly into gas – no melting of material | CO₂ Laser, Nd:YAG Laser |
| Remote Laser Cutting | Melts thin material using beam only (no assist gas) | Fiber Laser |
| Oxygen Laser Cutting | Heats and oxidizes material using oxygen gas | CO₂ Laser, Fiber Laser |
How to Choose the Right Laser Cutting Method?
Selecting the appropriate laser cutting method can be a confusing process. Due to confusion, you might end up choosing the wrong type of laser. It will affect both the quality of cuts and the budget of your project. Here are some key factors to consider when selecting a laser cutting method. It will help you choose the right type for your needs
- Material Type: First, you must determine the type of material you are working with. If you have a non-metal material, I recommend choosing a CO₂ laser. On the other hand, fiber laser cutting is best suited for metals and highly reflective materials.
- Material Thickness: The efficiency of a laser cutting method differs when the material thickness changes. You should choose crystal or fiber lasers for heavier and thicker materials. On the flip side, DDL (Direct Diode Laser) is the best option for thin materials.
- Production Volume: Each laser cutting method has its own limitations on the production volume it can handle. I recommend choosing a fiber laser cutting method if you have established a business. This method enables you to cut more parts in less time, allowing you to meet even the strictest deadlines.
- Precision & Quality: Manufacturers generally prefer precision and quality of cuts during manufacturing. Right? If that’s your requirement, you should choose crystal laser cutting. Although it is expensive, it would produce fine, detailed, and smooth cuts due to its higher beam quality.
- Budget and Speed: I consider the fiber laser as the best option, as its cost is mid-range and offers breakneck speed. CO₂ laser cutting is less expensive but slower, which can affect productivity. The crystal laser cutting is premium and very expensive, which I don’t recommend.
Conclusion
Laser cutting techniques play a crucial role in the fabrication of metals. The high-powered laser beam can easily cut material of any strength with ease. However, different types of laser cutting vary in terms of their effectiveness. Some of them are suitable for cutting metal materials.
On the other hand, some laser cutting methods excel when cutting non-metallic materials. In this article, I’ve explained the four significant types categorized by their laser source. This article also provides an overview of laser types based on their cutting capabilities. Lastly, you’ll learn about which laser cutting technique is best suited for your needs.