Only in recent years has fiber laser cutting technology begun to be widely used in industry.
Many companies have realized the advantages of fiber lasers.
With the development of cutting technology, fiber laser cutting has become one of the most advanced technologies in the industry.
In 2014, fiber lasers surpassed CO 2 lasers to occupy the majority of the laser source market.
Plasma, flame and laser cutting techniques are three common thermal cutting methods, while laser cutting can achieve the best cutting quality, especially for fine cutting and erasing holes with a diameter-to-thickness ratio of less than 1:1.
Therefore, laser cutting technology is also the first choice for fine cutting.
Fiber laser cutting has attracted great attention in the industry because it provides cutting speed and quality that can be achieved by CO2 laser cutting, significantly reducing maintenance and operating costs.
Laser Cutting Machine Market and Trends
Currently, there are 2 main types of laser cutting machines for sheet metal cutting in the sheet metal processing industry.
One is a CO 2 laser cutting machine that was converted from an industrial laser about 25 years ago, and the other is a fiber laser cutting machine that was officially converted from an industrial laser about 10 years ago.
Of the number of laser cutting machines sold in China's sheet metal equipment market in recent years, CO2 laser cutting machines account for 40% and fiber laser cutting machines account for 60%.
Although essentially 100% of laser cutters sold on the market in 2007 were CO 2 laser cutters, we know that fiber laser cutters have gained momentum in recent years and are gaining market acceptance and the number of units sold is gradually increasing.
Fiber Laser vs. Fiber Laser CO 2 laser
Although the current market trend favors fiber laser cutters, are fiber laser cutters really the best choice?
Due to the different physical characteristics of CO2 laser and fiber laser, the laser processing process differs between the two.
Of course, the two have their own strengths and weaknesses, and each has advantages and disadvantages depending on the object being processed.
C medium lengths
CO 2 laser is a gas beam obtained by exciting carbon dioxide molecules and its wavelength is 10.6μm while fiber laser is a solid laser obtained by placing a crystalline compound of Yb (ytterbium) as a medium in the fiber optics and irradiating the crystals with a beam of light, and its wavelength is 1.08μm .
The physical characteristics of the different wavelengths have a significant impact on the processing characteristics of the two.
The original concept of the fiber laser was recognized because it was a laser that could propagate through fibers.
The reason it is able to propagate through optical fiber is precise due to its wavelength of 1.08 μm.
laser transmission
The advantage of using optical fibers for propagation is the long service life of the optical components and the high reliability and low maintenance requirements.
CO2 laser cutting machines transmit laser light from the oscillator to the processing point with the aid of a reflective lens, usually in an optical path isolated from the outside air.
Although the interior of the optical path is filled with air free from common dust and foreign objects, the surface of the reflector may become covered with dirt even after prolonged use and needs to be cleaned.
Additionally, the reflector itself will wear out due to absorbing small amounts of laser energy and will need to be replaced.
To transmit the laser from the oscillator to the processing point, multiple reflectors are used to adjust the laser reflection angle.
Therefore, maintaining proper operations requires a certain amount of technical and management skills.
However, with fiber laser cutters, the laser is transmitted through a single fiber from the oscillator to the point of processing. This fiber is commonly called light guide fiber.
Because no optical components such as reflectors are required and the laser is transmitted in a light guiding fiber isolated from the outside air, the laser is virtually invisible.
Strictly speaking, however, the laser is repeatedly transmitted to the periphery of the optical fiber, so that the optical fiber itself is somewhat depleted. However, it will last much longer compared to the reflectors used in CO2 laser cutters.
Furthermore, if the transmission path is above the minimum curvature of the guide fiber, the path can be determined freely, making adjustment and maintenance easier.
Laser generation
The two also differ in the laser generation process (construction of the laser oscillator).
A CO 2 laser oscillator generates a laser by placing a gas mixed with CO 2 into the discharge space. To ensure proper functioning of the resonance length derived from the laser output power, optical components are placed inside the oscillator, which need to be cleaned and replaced periodically.
In contrast, fiber laser oscillators generate the laser inside the fiber and are isolated from the outside air with no optical components. Therefore, there is little need for regular maintenance. The maintenance cycle for cleaning is set at approximately 4,000 hours for CO 2 laser oscillators and approximately 20,000 hours for fiber laser oscillators.
The aforementioned advantages make fiber laser cutters more durable and easier to maintain.
Energy consumption
Furthermore, we can compare them in terms of operating costs such as energy consumption.
CO2 laser oscillators have a photoelectric conversion rate of about 10-15%, while fiber laser oscillators have a conversion rate of about 35-40%. This high photoelectric conversion rate of fiber laser cutters results in lower power consumption of cooling devices such as chillers as less electrical energy is converted into heat dissipation.
Although a fiber laser cutter's oscillator requires more precise cooling temperature management than a CO2 oscillator, about 1/2 to 2/3 of the cooling capacity of a CO2 laser oscillator is sufficient to a fiber laser cutter with the same laser output power.
Therefore, a fiber laser cutting machine can be operated with about 1/3 of the energy consumption of a CO machine. 2 laser cutting machine. This makes it a highly energy-efficient laser cutting machine.
Differences in processing characteristics
Cutting speed
There is a significant difference between CO 2 lasers and fiber lasers in their processing, mainly due to the difference in their respective wavelengths.
Processing speed comparison between CO2 laser cutting machine and fiber laser cutting machine when processing stainless steel.
Both lasers have an output of 4kW.
It can be seen that the fiber laser cutting machine is capable of processing 2 to 3 times the cutting speed of the CO2 laser cutting machine in the area of sheet thickness of 4.0 mm or less.
Why is there such a big difference in processing speed even with the same output power?
Firstly, the difference can be attributed to the large differences in the absorption rate of laser energy in metallic materials.
Due to the different physical properties of matter, the absorption of light energy at different wavelengths of light differs. For example, stainless steel has an absorption rate of about 12% for CO2 lasers, while fiber lasers have an absorption rate of about 35%, which is about three times higher.
This high absorption rate results in a very short time for the laser to convert light energy into thermal energy and melt the metallic material after irradiation, allowing for a very fast cutting process.
If you want to cut quartz glass with a laser cutter, you can use a CO2 laser cutter, but not a fiber laser cutter.
This is because quartz glass absorbs the wavelength of a CO 2 laser, but not that of a fiber laser, which penetrates it.
Furthermore, when cutting highly reflective materials such as aluminum and copper, fiber laser cutting has an advantage over CO2 laser cutting due to the principle that metallic materials absorb the fiber laser wavelength better.
When comparing the processing speed of stainless steel materials, it can be seen that the two speeds are essentially the same for sheet thicknesses above 6.0mm.
Cutting techniques
When cutting with a laser, it is more important to consider how to remove molten metal efficiently than how to melt the metal instantly.
During laser cutting, an auxiliary gas (usually nitrogen, oxygen, etc.) is injected into the processing point while the laser is directed at the material to achieve ideal processing conditions.
Different auxiliary gases are used for different cutting materials. The main function of the auxiliary gas is to isolate the molten metal from the lower part of the material.
For thick sheets, an assist gas is required to achieve ideal cutting conditions, isolating the molten metal from the bottom of the material, ultimately increasing processing speed.
However, in terms of processing area and cutting quality, CO 2 laser cutting machines are generally considered superior.
It has been approximately 30 years since the introduction of CO 2 laser machines to industry and their characteristics have been thoroughly studied, allowing them to process a wide range of materials, from thin to thick sheets. Furthermore, processing technology has become so mature that it can guarantee a certain processing quality.
We have not only developed the processing technology to cut various shapes, but also to ensure a certain roughness of the cutting surface.
However, ensuring cutting quality with fiber laser cutting machines still presents some challenges. In particular, for products processed with fiber laser cutting machines and with a plate thickness greater than 3.0mm, there will be some visible small particles attached to the bottom of the cutting surface that are difficult to remove, known as foam. . The cutting surface is also rougher compared to that of CO 2 laser cutting machines. This phenomenon is caused by the high absorption property of metallic materials.
During laser processing, the laser reflects off the surface of the material and the metal melts and falls off. When a fiber laser reflects off a metal surface with high absorption rates, back-absorption occurs, melting the metal on the cutting surface and resulting in a rough cut section after cutting.
Sample cut by CO 2 laser cutting machine (stainless steel 20mm)
Processing quality is one of the difficult items to quantify, which is why many customers do not pay much attention to it when choosing a laser cutter.
However, the above-mentioned problem with slag is related to the processing quality.
Fiber laser cutting machines can be used to control costs even at high speeds. After the laser cutting process, if there is a subsequent process such as foam removal, the total processing cost will be approximately the same as that of a CO2 laser cutting machine.
Therefore, it is necessary to pay more attention to the processing quality of the laser cutter.
Laser cutting machine kinematics
Although I used the concepts of fiber lasers and CO 2 lasers to make a comparison, is it enough to rely on this alone when choosing a laser cutter?
The comparison of fiber optics and CO 2 refers to the constituent oscillators of a laser cutter. In the composition system of a laser cutting machine, there are also X, Y, Z drive axes. The performance and movement control of these drive axes are also significant factors.
Laser cutting machines can process complex shapes such as odd-shaped holes, wedges and protrusions, as well as round, square and rectangular holes.
Therefore, no matter how fast the machining speed is, if the kinematic performance of the XY drive axis, which determines the shape to be machined, is low, it is impossible to shorten the cutting time.
If the processing speed is 40m/min with a fiber laser machine and 20m/min with a CO 2 laser cutting machine, the processing time of the fiber laser machine will not necessarily be twice as fast as The CO 2 laser cutting machine and the processing time of the CO 2 laser cutting machine will not necessarily be half as fast when processing a certain shape, especially if the machining shape is complex and the number of holes is high .
To clearly show the difference in processing speed, it is necessary to improve the kinematic performance of the transmission shaft, especially the acceleration and deceleration ability during cutting processing.
Combined capabilities of laser cutting machines
With high acceleration and deceleration performance, a strong and highly rigid structure is required to support its kinematic performance. To maintain product processing accuracy, it is necessary to have an internal structure that can control high movements.
Maximizing the laser processing capacity of the oscillator requires an increase in the overall capacity of the laser cutting machine, including the drive shaft.
Because the components of a fiber laser cutter are relatively simple, it is possible to build a fiber laser cutter of a certain quality without laser processing technology when considering the design and manufacture of a laser cutter.
Furthermore, many components of a fiber laser cutting machine are available on the market, and the processing capacity of a cutter made by assembling these components is also good. This is one of the reasons why there has been a recent proliferation of manufacturers that make and sell fiber laser cutters.
However, CO2 laser cutting machines require many processing techniques such as laser transmission, so it is easy for differences in characteristics and performance to occur between laser cutting machine manufacturers.
A true laser cutting machine manufacturer must have mature technology and ability to design and manufacture CO 2 laser cutting machines, as well as the processing technology accumulated in the production of CO 2 laser cutting machines that can be used to design and manufacture fiber laser cutting machines.
Although machining accuracy and quality are difficult to express numerically, the best choice is a laser cutting machine that can consistently maintain a high level of precision and quality as well as high kinematic performance. However, it is necessary to make a rational decision based on the processing materials.
If the material to be processed is thin, the production volume is high, and you want to control processing costs, a fiber laser cutter is the best choice. However, if in many cases a thickness greater than 6.0 mm is required or a certain processing quality is required, a CO 2 laser cutting machine is more suitable.
Separate follow-up operations are required and the total processing cost is very high when done manually. When selecting a laser cutting machine, make comprehensive assessments not only of the laser process, but also of your product and manufacturing.
The Advantages of F Fiber Laser C Revealing
The technology provides the speed and cutting quality that carbon dioxide laser cutting can achieve, while significantly reducing the cost of maintenance and operation.
The most significant advantage of fiber cutting technology is its energy efficiency. For each unit of energy in the carbon dioxide cutting system, the actual overall utilization rate is about 8% to 10%. In return, the user can expect higher energy efficiency with the fiber laser cutting system, which is around 25% to 30%.
In other words, the overall energy consumption of the fiber cutting system is about 3 to 5 times lower than that of the carbon dioxide cutting system, resulting in an increase in energy efficiency to more than 86%.
Fiber lasers have short wavelength characteristics that increase beam absorption by the cutting material and can cut materials such as brass, copper and non-conductive materials. A more focused beam produces a smaller focus and deeper focal depth, allowing the fiber optic laser to quickly cut thin materials and more efficiently cut medium thickness materials.
When cutting materials up to 6 mm thick, the cutting speed of a 1.5 kW fiber laser cutting system is equivalent to that of a 3 kW carbon dioxide laser cutting system. As the operational cost of fiber cutting is lower than that of common carbon dioxide cutting systems, this can be understood as an increase in production and a decrease in commercial cost.
There are also maintenance issues to consider. The CO2 laser system requires regular maintenance, including reflector maintenance and calibration, as well as regular resonant cavity maintenance. However, the fiber laser cutting solution requires virtually no maintenance.
The CO2 laser cutting system requires CO2 as the laser gas, and due to the purity issues of the CO2 gas, the cavity can become contaminated and require regular cleaning. It costs at least $20,000 a year for a kilowatt carbon dioxide system. Additionally, many CO2 cuts require high-speed axial-flow turbines to deliver laser gas, and the turbines require maintenance and renewal.
Finally, compared to CO2 cutting systems, fiber cutting solutions are more compact and have less impact on the environment, requiring less refrigeration and significantly reducing energy consumption. Lower maintenance and higher efficiency characteristics make fiber optic laser cutting systems more environmentally friendly, emitting less carbon dioxide than CO2 laser cutting systems.
Fiber lasers have a wide range of applications, including fiber laser communication, industrial shipbuilding, automobile manufacturing, sheet metal processing, laser engraving, medical equipment, and more. As the technology continues to develop, the range of applications for fiber lasers is expanding.
CO 2 Laser versus fiber laser: which is better?
fiber laser
Fiber laser definition:
A fiber laser is a type of laser that uses fiberglass doped with rare earth elements as a gain medium. Fiber lasers can be developed based on fiber amplifiers.
Fiber laser principle:
Under the action of pump light, a high power density can be formed in the optical fiber, leading to the “particle number inversion” of the laser energy level of the laser work material. When the positive feedback circuit (forming a resonator) is added correctly, laser oscillation output can be generated.
Fiber laser applications:
Fiber lasers have a wide range of applications, including fiber laser communication, laser space long-distance communication, industrial shipbuilding, automobile manufacturing, laser engraving, laser marking, laser cutting, printing roller, drilling/cutting/welding of metals and non-metals (brazing, quenching, coating and deep welding), military and national defense security, medical instruments and equipment, and large-scale infrastructure construction, as well as the pump source of other lasers.
Fiber Laser Types:
Fiber lasers can be classified in several ways, among which the most common methods include classification by working mode, bandwidth, and dielectric doped rare earth elements.
Fiber lasers can be classified in several ways, including:
By work mode:
- Continuous fiber laser (used for laser cutting, welding, cladding)
- Quasi-continuous fiber laser (used for spot welding, seam welding, drilling)
- Pulsed fiber laser (used for micromachining of materials, scalpel, microscope, laser measurement)
By band range:
- Mid-infrared fiber laser (used for medical laser sources and laser guidance)
- Green fiber laser (used for medical imaging diagnosis and holographic projection)
By doped rare earth elements:
- Ytterbium-doped fiber laser (used for industrial processing, medical treatment and national defense)
- Erbium-doped fiber laser (used for laser environmental monitoring)
- Tm-doped fiber laser (used for laser fine cutting and laser hemostasis)
Lasers are often named based on one or more of these categories.
Fiber lasers have a wide range of applications, and different subdivisions of lasers have distinct characteristics and suitable fields of application. For example:
- The mid-infrared range is safe for human eyes and can be strongly absorbed by water, making it an ideal medical laser source.
- Erbium-doped fiber is widely used in the field of optical fiber communication because of its suitable wavelength.
- The green laser is essential in entertainment and projection due to its visibility.
An application diagram of the laser subdivision classification corresponding to relevant industries may be helpful in identifying suitable uses for specific types of lasers.
CO2 I aser
A CO2 laser is a type of molecular laser and is one of the most common high-power continuous wave (CW) lasers. Its main material is carbon dioxide molecules.
The main structure of a CO2 laser includes a laser tube, an optical resonator, a power supply and a pump. Its main feature is high output power and continuous operation, but the structure is complex and the laser is large and difficult to maintain.
Basic structure of CO 2 gas laser
Performing particle number inversion is essential for the luminescence of a carbon dioxide laser.
The working substances in a carbon dioxide laser include carbon dioxide, nitrogen and helium.
After DC power is supplied, nitrogen molecules in the mixed gas are excited by the impact of electrons.
When excited nitrogen molecules collide with carbon dioxide molecules, they transfer energy to the carbon dioxide molecules.
Thus, carbon dioxide molecules transition from a low energy level to a high energy level, forming an inversion in the number of particles and emitting a laser.
① Nitrogen molecules collide with carbon dioxide molecules after excitation, so that carbon dioxide is excited separately.
② The excited carbon dioxide molecule jumps and emits a laser
Fiber Laser vs. Fiber Laser CO2Laser
Optical fiber and CO2 laser has its own advantages, and different lasers should be selected according to different needs.
Of the currently widely used cutting technology, fiber laser and CO 2 laser have their own advantages and disadvantages in the face of specific application requirements.
They cannot completely replace each other, but they need to complement each other and coexist.
By the type of processing material, due to the absorption effect, fiber lasers are not suitable for cutting non-metallic materials, while conventional CO 2 lasers are not suitable for cutting high-reflectivity materials such as copper and aluminum.
In terms of cutting speed, CO2 lasers have advantages at sheet thicknesses > 6 mm, while fiber lasers cut sheets faster;
Part penetration is required before laser cutting and the drilling speed of CO2 is significantly faster than fiber laser;
In terms of cutting section quality, CO2 laser is better than fiber laser as a whole.
Comparison Between Fiber Laser and Carbon Dioxide Laser
| fiber laser | CO 2 laser | |
| Cutting material | Non-metallic materials cannot be cut | Highly reflective materials have poor adaptability |
| Cutting speed | Obvious advantages below 3mm | >6 mm, CO 2 is more advantageous |
| Penetration efficiency | The speed is relatively slow | The greater the thickness, the more obvious the advantage |
| Section quality | A little worse | Better roughness and verticality |
Fiber laser has higher light conversion efficiency and lower use cost.
Based on calculation, the cost of using fiber laser is 23.4 yuan per hour, while the cost of using carbon dioxide laser is 39.1 yuan per hour. Specifically, the energy cost of fiber laser is 7 yuan per hour, the water cooling cost is 8.4 yuan per hour, and other costs are 8 yuan per hour. Meanwhile, the energy cost of carbon dioxide laser is 21 yuan per hour, the water cooling cost is 12.6 yuan per hour, and other costs are 5.5 yuan per hour.
Cost Comparison Between Fiber Laser and CO2 Laser
| fiber laser | CO2Laser | |
| Power (kw) | 3 | 3 |
| Light Conversion Efficiency | 30% | 10% |
| Power consumption (kw) | 10 | 30 |
| Electricity price (yuan/kWh) | 1 | 1 |
| Charging duration | 70% | 70% |
| Energy cost (yuan/hour) | 7 | 21 |
| Power of water cooling equipment (kw) | 12 | 18 |
| Electricity price (yuan/kWh) | 1 | 1 |
| Charging duration | 70% | 70% |
| Water cooling cost (yuan/hour) | 8.4 | 12.6 |
| Consumables cost (yuan/hour) | 3 | 2.5 |
| Module consumption cost (yuan/hour) | 5 | |
| Media cost (yuan/hour) | 1 | |
| Conventional point solution (yuan/hour) | two | |
| Other costs (yuan/hour) | 8 | 5.5 |
| Usage cost (yuan/hour) | 23.4 | 39.1 |
