Using laser as a medium for material cutting, you must want to know everything about this machining method. Today, i will explain in detail what laser cutting is? What are its working principles, advantages and application directions?
What Is Meant By Laser Cutting?
Laser cutting is an advanced machining technology that uses a high-energy laser beam to cut materials. Its working principle is to focus the beam emitted by the laser onto the target material through the lens, forming an extremely small spot of light. The temperature of this light spot is extremely high and can quickly melt or vaporize the material. At the same time, laser cutting is widely used in many industries, and its main feature is that it can quickly cut complex shapes with minimal material waste.
How Does Laser Cutting Work?
After talking about the definition of laser cutting, I will introduce to you how laser cutting works?
1. Laser Generation
From the beginning, it was about the work of the laser. The laser generates a laser beam by excitating a medium such as a gas, solid, or liquid. As for which type of laser to choose (such as CO2 laser and fiber laser, etc.), it is determined based on the material and application needs.
2. Beam Focusing
The laser beam is focused through the lens system, forming a very small spot of light. The diameter of this light spot is usually between a few microns and a few millimeters, and the energy density is very high, reaching several kilowatts per square centimeter, so the material can be heated quickly.
3. Material Heating
The focused laser beam will be illuminated onto the target material. When laser energy is absorbed by the material, it will cause the surface of the material to heat up rapidly. The absorption rates of different materials are also different. Metals have lower absorption rates, while plastics and wood have higher absorption rates. Then, as the surface temperature continues to rise, the material will melt or even gasify. At this time, the laser beam will form a cutting path on the material.
4. Gas-Assisted Cutting
At this point, the formal cutting process has arrived. During the process, you need to use auxiliary gases (such as oxygen, nitrogen or air). These gases are generally used to remove molten materials and improve the cutting quality.
5. Cutting Process
The computer-controlled laser beam will accurately move and cut along a predetermined cutting path, and as the laser light continues to irradiate, the material is continuously cut, eventually forming the desired shape and profile.
6. Cooling And Post-Treatment
After the entire cutting process is completed, the finished product needs to be cooled and post-treated. You may also need to remove the slag and burrs generated during the process to achieve better surface quality.
Methods Of Laser Cutting
As you have learned above, laser cutting is an efficient material machining technology. It has many different methods and techniques, and I will introduce them one by one next.
1. Gas Laser Cutting
Gas laser cutting is very suitable for cutting metal, with fast cutting speed, good quality and low cost. It uses gas lasers, such as CO₂ lasers, to generate laser beams. The excitation medium is a gas mixture (such as carbon dioxide, nitrogen and helium).
2. Fiber Laser Cutting
Fiber laser cutting has high cutting accuracy and is very suitable for machining parts of complex shapes. Its working principle is that fiber lasers transmit laser beams through optical fibers, and also have the characteristics of low energy consumption, high efficiency and low maintenance costs.
3. Solid Laser Cutting
Solid laser cutting uses solid crystals as excitation medium and uses solid lasers (such as Nd:YAG lasers) to complete the overall cutting operation. Because this process has the characteristics of fast cutting speed, it is also commonly used in metal and non-metallic materials. At the same time, the cutting depth of solid laser cutting is also relatively deep, so materials with larger thickness are also suitable.
4. Pulse Laser Cutting
Pulse laser cutting is to accurately cut the material by emitting high-energy laser pulses in a short time. Since this process can cut without damaging the material, materials such as plastics and paper are very suitable. At the same time, it has a high cutting accuracy and can handle parts with patterned designs very well.
5. Continuous Laser Cutting
Continuous laser cutting, as the name suggests, uses a continuously emitted laser beam to cut. The result is fast cutting speeds and is very suitable for mass production. Another thing you need to note is that the cutting edges of the process are smooth, so the need for post-processing is reduced.
Main Parameters of Laser Cutting
Parameters are also a link that cannot be ignored in laser cutting. I believe that through learning the content of this module, you will be of great benefit.
1. Laser Power
Laser power, simply put, is the rate at which the laser outputs energy. The higher the power, the greater the thickness of the cut material. When cutting thin plates, low power (500W~2000W) is usually used, while when cutting thick plates, high power (3000W~6000W or higher) is required.
2. Cutting Speed
The cutting speed refers to the speed of the laser head moving along a predetermined trajectory, usually expressed in millimeters/second (mm/s) or meters/minute (m/min). And you need to note that the speed is inversely proportional to the laser energy input per unit length, that is, the slower the speed, the longer the action time, the more energy it inputs.
3. Laser Wavelength
Laser wavelength refers to the wavelength of the laser beam, usually in units of nanometers (nm). Common ones include carbon dioxide lasers (10.6μm), fiber lasers (1064nm), and semiconductor lasers (800~1000nm). Different wavelengths are also suitable for different materials.
4. Focus Spot Diameter
The meaning of focusing spot diameter refers to the spot diameter formed after the laser beam is focused. The size of the light spot is affected by the lens focal length and beam quality. The smaller the light spot, the higher the cutting accuracy.
5. Assist Gas Type and Pressure
Assist Gas Type and Pressure refers to the type and pressure of auxiliary gas used during the cutting process. First, I will focus on introducing these gas types to you.
- Oxygen (O₂): Oxygen undergoes a violent oxidative exothermic reaction with the molten metal, thereby providing additional heat and enhancing cutting ability. Mainly used for cutting carbon steel.
- Nitrogen (N₂) : Nitrogen, as a protective gas, can prevent the material from oxidizing at high temperatures, and ensure bright and non-oxidized layers. Therefore, it is very suitable for cutting stainless steel, aluminum alloy, brass and other materials.
- Compressed air (Air): The ingredients are mainly nitrogen and oxygen. The cost is very low and it is very suitable for cutting thin plates (such as carbon steel, stainless steel thin plates, etc.).
Secondly, with regard to pressure, its main function is to blow away the molten metal slag and cool the cutting area. The pressure range is generally 0.5~6 bar, depending on the material and thickness.
6. Focus Position
Focus position, which means the height of the laser beam focusing point relative to the material surface. The types of focus points are mainly divided into positive focus (focus point on the surface of the material), negative focus (focusing point inside the material), and zero focus (focus point on the edge of the material).
What you need to understand is that the focus position directly affects the width and shape of the cut seam, and improper position adjustment can lead to a decrease in cut quality.
7. Nozzle Type & Diameter
The main types are divided into single-layer nozzles and double-layer nozzles. The single-layer nozzle is mainly used for melting cutting, with small gas diffusion and is suitable for high-pressure gases; The double-layer nozzle is used for oxidation cutting, with large gas diffusion and is suitable for low-pressure gases.
As for the nozzle diameter, it determines the gas outflow form and velocity. If your choice is inappropriate, it will affect the effect and stability of the slag discharge.
8.Material Thickness
The thickness of the material is also one of the important factors. It is obvious that this refers to the thickness of the material being cut. The greater the thickness, the higher the laser power and slower the cutting speed.
Advantages Of Laser Cutting
1. High Precision
The laser beam can be focused to a very small spot (less than 0.1mm), thereby achieving extremely high machining accuracy. Tolerances can usually be controlled within ±0.1mm.
2. High Quality
Usually after the entire laser cutting process is completed, the cutting edges of the final parts are smooth, flat, and burrs-free, and there is almost no follow-up processing such as secondary grinding or polishing, which greatly shortens the production cycle. At the same time, since the heat-affected zone during the cutting process is small, the possibility of material deformation is very low, which also ensures the cutting quality of the parts.
3. Non-Contact Machining
Laser cutting is a non-contact machining, and the laser head does not directly contact the material, so it also avoids mechanical damage to the material. This is also especially suitable for machining thin plates, fragile or high precision parts.
4. Fast Cutting Speed
The speed of laser cutting is far beyond traditional mechanical cutting, especially when cutting thin plates, which can achieve a cutting speed of several meters per minute.
5. Extremely High Flexibility
This is one of the most significant features of laser cutting. This process can machining complex patterns of various shapes, which is very suitable for customized production. In addition, laser cutting does not require molds, allowing you to modify the CAD drawing design at any time and put it into production immediately.
6. High Degree Of Automation
Laser cutting is highly automated, and it will be perfectly combined with computer CNC technology (CNC) to achieve highly automated production. During this period, you only need to use software control, and the machine can automatically complete all operations, and support rapid design modification and improve production flexibility.
7. Small Heat Affected Zone
Since the laser energy is highly concentrated, the working time is extremely short, so the heat transferred to the non-cut areas of the material is very small.
8. Wide Range Of Materials
Laser cutting supports a variety of materials, and common metal materials include carbon steel, stainless steel, aluminum alloy, brass, etc. Non-metallic materials include acrylic (plexiglass), wood boards, plastics, leather, fabrics, paper, etc.
9. High Material Utilization
Because the cutting seam of laser cutting is very narrow, the material utilization rate is high, and the machine can also optimize the overall layout with the help of advanced nesting software, which can closely arrange the parts on the plate, further reducing the generation of scrap.
10.Environmental Friendly
Laser cutting is also very environmentally friendly. There is little waste generated in the entire production process, and the cutting process is clean and chemical reagents are not required during the period. In addition, the impact of auxiliary gases on the air environment is almost negligible.
Applications Of Laser Cutting
Having said so much, you must be curious about which industries are suitable for laser cutting technology. I will give you one by one in the future.
1. Sheet Metal Fabrication
Sheet metal fabrication can be said to be the most core and widest application field. Laser cutting almost completely changes the traditional sheet metal processing mode, with fast cutting speed and high accuracy, which can ensure the consistency of parts. At the same time, it can also manufacture shells, chassis, cabinets, electrical control boxes, metal parts, etc. of various mechanical equipment.
2. Automotive Industry
In the automotive manufacturing industry, laser cutting plays an important role in making wide range of automotive components..It can cut high-strength steel plates such as body covering parts, chassis parts, doors, trunk covers, etc., and also supports trimming and opening holes in stamped parts.
3. Aerospace Industry
Laser cutting has the typical characteristics of high precision, which is very consistent with the needs of the aerospace industry. It can cut special aviation materials such as titanium alloy, nickel-based superalloy, and aluminum alloy intact, and manufacture aerospace products such as engine parts, fuselage structural parts, turbine blades, etc. In addition, since the process uses a non-contact processing mode, damage to expensive materials is avoided. It can be said that it is very practical.
4. Manufacturing Industry
Today, laser cutting can be said to be widely used in the manufacturing industry. It can accurately cut various metal materials, including stainless steel, aluminum and copper, and can also efficiently cut various plastic products.
5. Medical Device Industry
Similarly, laser cutting is also used in the medical industry. After all, medical devices have extremely high requirements for safety and cleanliness, while laser cutting characteristics can be perfectly met. It can manufacture housing and internal components such as surgical tools, orthopedic implants (such as bone plates), vascular stents, endoscopic parts, and various precision medical instruments. Moreover, the cuts of medical products are very smooth, easy to disinfect and will not cause material contamination.
6. Electronics & Electrical Industry
Yes, laser cutting is also used in the electronics and electrical industries. Today’s electronic products are pursuing lightweight and precision, so laser cutting technology is becoming more and more important. It can be used to cut precision metal parts such as the middle frame of the phone, internal metal bracket, shield cover, precision stainless steel gasket, etc. As for precision circuit boards (PCBs), it is also suitable.
7. Advertising, Decoration & Signage
In the advertising industry, laser cutting can be used to make metal advertising characters, company logos, hollow screens, art decorative boards, signboards, etc. Any complex graphic and text design can be easily handled, and the cutouts are smooth and beautiful in appearance.
8. Textile & Apparel
Finally, there is the textile industry. Laser cutting can accurately cut and sample flexible materials such as fabrics, leather, and non-woven fabrics. Even when cutting chemical fiber fabrics, it can prevent the edges of the fabric from defilmenting.
What Is A Laser Cutting System?
Now, you must have questions, what are the components of laser cutting systems? I will answer you next.
- Laser Source: equipment that provides laser beams, common ones include CO2 lasers and fiber lasers
- Optical System: used to focus the laser beam to ensure that the laser energy can be focused on the material
- Motion Control System: controls the movement of the laser head on the material through computer instructions
- Cooling System: Ensure the constant temperature of the laser and other components so that the equipment can operate safely
- Smoke Exhaust System: During the laser cutting process, smoke will be generated by the material, and the smoke exhaust system is used to exhaust these gases
What Are The Dangers Of Laser Cutting?
So, after talking about such useful advantages, what are the dangers of laser cutting? I will clarify this so that you can also understand this and prevent these situations from occurring.
1. Eye Damage
The first is the damage to the eyes. Everyone knows that laser cutting requires a laser beam to complete the operation, but the laser beam will produce strong light, which may cause serious damage to the eyes. If the operator accidentally contacts the laser beam directly, it is very likely to cause permanent visual damage. So you must always beware of this dangerous situation
2. Fire Risk
Then there is the fire danger.Since the material is directly exposed by the laser during the laser cutting process, this leads to an increase in the surface temperature of the material, which will undoubtedly lead to fire, especially when cutting certain flammable materials, the risk of fire is even higher.
3. Harmful Gases And Smoke
The third point is smoke. During laser cutting, some materials produce harmful gases and fumes, which can be harmful to the operator’s health.Therefore, you must pay attention to using the smoke exhaust system and ensure good ventilation in the entire workshop. At the same time, you must strictly require the operator to wear respiratory protection equipment.
4. Mechanical Damage
Since the laser cutting system is equipped with moving parts and the operator operates improperly, it may lead to mechanical damage. For example, accidentally touching a cutting tool or moving part can lead to a cut.
5. Electrical Hazards
Normally, laser cutting equipment requires high voltage power supply, which poses an electrical hazard. If the operator accidentally misoperates, it may cause an electric shock hazard. Therefore, this requires enterprises to formulate correct electrical safety operating specifications.
6. Noise Damage
Noise will also be generated during laser cutting. If the operator is exposed to noisy environment for a long time, this will undoubtedly affect their hearing, so the operator needs to wear noise reduction equipment and implement noise reduction measures.
7. Materials Hazard
Yes, materials can sometimes cause dangerous situations, especially plastics or metals with reflective surfaces. These materials have a certain chance to reflect the laser beam, which can cause harm to the operator and the equipment. Therefore, you should also consider this uncertainty.
In Conclusion
In short, laser cutting is a processing technology with high efficiency, good cutting effect and wide application. Nowadays, more and more manufacturers choose this method to complete mass production and customized processing, and our DSR company is no exception. Over the years, we have provided laser cutting services for more than 100 companies from all over the world, and the excellent product quality is well received by them. If you need it, come and communicate with us!
FAQ
Q1: Why is laser cutting better than 3D printing?
A: Compared with 3D printing, laser cutting has many obvious advantages.
First, laser cutting can machining various materials faster and with high precision, suitable for large-scale production and complex shape cutting.
Second, laser cutting is suitable for many materials, such as metal, plastic, wood, etc., while 3D printing has much fewer materials to choose from.
Third, the product after laser cutting has a very good effect, and the cut edge is smooth, which reduces the need for post-processing.
Fourth, it is the issue of efficiency. Laser cutting is very efficient and can quickly produce large batches of the same parts.
So now you finally understand what kind of process you should use to produce.
Q2: How much does it cost for laser cutting?
A: The cost of laser cutting is determined by factors such as material type, cutting thickness, complexity and processing time, and the cost of equipment usage and maintenance also needs to be taken into account.Generally, laser cutting typically costs between $10 and $100 per square foot. For example, metal cutting can cost $20 to $100 per square foot, while plastic and wood are relatively inexpensive, typically at $10 to $30 per square foot. In addition, the price range of laser cutting machines is between $2,000 and $200,000.
Q3: Which is better CO2 or RF laser cutter?
A: First of all, you need to understand that CO2 laser cutting machines and RF (radio frequency) laser cutting machines have their own advantages and disadvantages.
CO2 laser cutting machines are suitable for a wider range of materials, including metals, plastics and wood. The initial investment and later maintenance costs are very low, so they are very suitable for small businesses and individual users. However, the disadvantage is that they are less efficient when cutting thick metals. Correspondingly, RF laser cutting machines have the characteristics of high power output, so they are very suitable for cutting thick metals. The quality of the laser beam is also very high, and it can complete the cutting operation very efficiently. However, the initial investment and post-maintenance costs of this machine are very high. So which machine you decide to use depends entirely on the scale of production you need and your budget.
