What Laser Can Cut Metal
Laser cutting technology has become a vital tool in metal processing industries, offering precision, efficiency, and versatility in handling various metal types. Among the most popular lasers used for cutting metals are fiber lasers, CO2 lasers, and YAG lasers. Each of these laser types operates based on different principles, with distinct features, applications, and advantages.
If you’re interested in a detailed comparison of how these three types of lasers perform when cutting metal, keep reading!
How Laser Cutting Works
Laser cutting is a technology that uses lasers to cut materials, commonly employed in industrial manufacturing. The process involves directing a high-power laser beam through an optical system onto the material’s surface, where it melts, burns, vaporizes, or is blown away by a gas jet, resulting in cutting edges with a high-quality surface finish. The cutting process is supported by an assist gas, such as oxygen or nitrogen, which helps blow away molten material and improves the cutting quality. The laser light used in cutting is controllable monochromatic light, characterized by high intensity and large energy density. When focused through an optical system, it can achieve immense power density, theoretically capable of cutting nearly all metals and non-metals. Industrial laser cutting machines are utilized for cutting sheet materials, as well as structural and piping materials. The main elements of laser cutting include:
- Laser Beam Generation: The laser source generates the energy required to produce the laser beam.
- Focusing: The beam is focused to a precise spot, allowing for high-energy density at the metal surface.
- Cutting Process: The laser’s energy melts or vaporizes the material, with the assist gas blowing away the debris.
Different lasers—fiber, CO2, and YAG—have distinct mechanisms to produce and direct the beam for metal cutting.
Fiber Laser Cutters: High Efficiency and Precision
Working Principle
Fiber laser cutting machines use a fiber optic cable doped with rare-earth elements (like erbium or ytterbium) to amplify light and generate the laser beam. Operating at a wavelength of around 1.064 microns, fiber lasers are particularly efficient for cutting metals due to their ability to deliver high energy density at the metal surface.
Features
- Energy Efficiency: Fiber laser cutters have a high electrical-to-optical conversion efficiency, making them more energy-efficient compared to other laser types.
- High Precision: The beam quality of fiber lasers is superior, allowing for precise and clean cuts.
- Minimal Maintenance: Since CNC fiber laser cutters have no moving parts or mirrors in the beam delivery system, they require less maintenance.
Applications
Fiber lasers excel in cutting a wide range of metals, including stainless steel, carbon steel, aluminum and galvanized sheet. They are widely used in industries such as aerospace, automotive, and electronics for sheet metal cutting, engraving, and precision welding.
CO2 Lasers: Versatile and Powerful
Working Principle
CO2 lasers use a gas mixture of carbon dioxide, nitrogen, and helium to produce a laser beam at a wavelength of 10.6 microns. The electrical energy excites the gas molecules, generating the laser beam that is then directed through mirrors to the cutting area. CO2 lasers are known for their ability to cut both metals and non-metal materials.
Features
- Versatility: CO2 lasers can cut metals as well as non-metals like wood, plastic, glass, and fabric, making them a versatile option for various industries.
- High Power: These lasers can handle thicker metals due to their high-power output.
- Good Edge Quality: CO2 lasers produce smooth cuts, especially when dealing with thicker metal materials.
Applications
CO2 lasers are commonly used in industries like shipbuilding, construction, and automotive for cutting thicker metals such as stainless steel, carbon steel, and aluminum. They are also extensively used for cutting non-metallic materials, making them suitable for sectors like textile manufacturing and signage.
Limitations
While CO2 lasers are versatile and powerful, they are less energy-efficient than fiber lasers. They also require more maintenance due to the presence of mirrors and gas systems, which need frequent adjustments.
YAG Lasers: Precision in Special Applications
Working Principle
YAG lasers (Yttrium Aluminum Garnet) are solid-state lasers that use a crystal as the gain medium. They are typically doped with neodymium (Nd) and operate at a wavelength of 1.064 microns, similar to fiber lasers. These lasers are capable of producing high peak power, making them ideal for both cutting and welding applications.
Features
- High Peak Power: YAG lasers can generate extremely high-power levels, suitable for precise and fast cutting or welding of metals.
- Minimal Heat Distortion: The focused beam of YAG lasers results in a smaller heat-affected zone (HAZ), which reduces thermal distortion on the workpiece.
- Specialized in Reflective Metals: YAG lasers are effective for cutting reflective metals such as aluminum, copper, and gold.
Applications
YAG lasers are commonly used in industries requiring high precision, such as the aerospace, electronics, and jewelry sectors. They are effective for cutting thin metals, micro-welding, engraving, and specialized tasks where precision is essential.
Limitations
YAG lasers are generally more expensive to operate compared to fiber lasers. They are less efficient in cutting thick metals and have slower cutting speeds compared to fiber and CO2 lasers. Additionally, YAG lasers require more maintenance due to their complex solid-state components.
Comparing Fiber, CO2, and YAG Lasers
Here’s a quick comparison of the three laser types based on key factors:
| Laser Type | Wavelength | Best For | Cutting Speed | Efficiency | Maintenance |
| Fiber Laser | 1.064 microns | Carbon steel, stainless steel, aluminum | Fast (exceptionally quick on thin metals) | High energy efficiency (due to direct delivery of energy to the workpiece) | Low (fewer moving parts, solid-state design) |
| CO2 Laser | 10.6 microns | Thick metals and non-metals (wood, plastic, glass, acrylic) | Moderate for metals, faster for non-metals | Medium energy efficiency (requires more power for metals) | High (regular upkeep required due to wear in optics, mirrors, and the CO2 gas |
| YAG Laser | 1.064 microns | Precision cutting, reflective and brittle metals (gold, silver, titanium) | Slow (used more for fine detailing) | Medium (solid-state, but less efficient than fiber lasers) | Medium (requires some upkeep but more durable than CO2 systems) |
Conclusion
When it comes to cutting metals, these three lasers each have their strengths and limitations. Fiber lasers are ideal for cutting metals with high speed, precision, and efficiency, making them the go-to choice for many modern applications. CO2 lasers excel at processing both metals and non-metals; however, due to their high energy consumption and maintenance costs, more and more customers are opting for fiber lasers to cut metals.
YAG lasers, with their precision and ability to cut reflective metals, remain valuable in niche applications.
By understanding the differences between these laser types, you can make an informed decision on which laser system best fits your metal cutting requirements.
