Friends who have been exposed to handheld laser welding machine may have heard of heat conduction welding and deep penetration welding. How should we choose between heat conduction welding and deep penetration welding when using laser welding?
- Heat conduction welding: Heat conduction welding is suitable for thin materials (approximately 1mm) and the welding of small components. When the laser is irradiated onto the material surface, a portion of the laser is reflected while another portion is absorbed by the material, converting the optical energy into heat to melt the material. Subsequently, the heat is conducted through the material in a conduction process, ultimately fusing the two welded pieces together.
- Deep penetration welding: Deep penetration welding is suitable for cases where the laser beam with a relatively high power density is needed. During the deep penetration welding process, the laser heats the material to the point of melting and vaporization, generating a large amount of metal vapor. As the vapor exits the surface, the resulting reactive force pushes the molten metal away, forming a cavity. With continuous laser irradiation, the cavity becomes deeper. When the laser stops, the molten liquid around the cavity flows back, solidifying and cooling to weld the two pieces together. Deep penetration welding is characterized by high efficiency and fast welding speed, with a minimal heat-affected zone and controlled deformation.
Heat conduction welding is suitable for thinner materials, while keyhole welding is more suitable for thicker materials. If a higher welding strength is required, keyhole welding may be more suitable as it can provide better weld seam quality and joint strength. Heat conduction welding has a smaller heat-affected zone, which helps reduce the possibility of deformation, while keyhole welding may introduce greater heat impact and deformation. Keyhole welding typically requires higher laser power, which may result in slower welding speeds, while heat conduction welding can often achieve faster welding speeds and higher production efficiency.
Therefore, when choosing between heat conduction welding and deep penetration welding, the following factors can be considered:
- Material thickness and size: Heat conduction welding is suitable for thin materials and small components, while deep penetration welding is more suitable for thicker materials.
- Welding efficiency and speed: Deep penetration welding offers high efficiency and fast welding speed, making it suitable for situations that require rapid welding.
- Heat-affected zone and deformation requirements: Both heat conduction welding and deep penetration welding have small heat-affected zones, but deep penetration welding offers better control over deformation.
Types of laser welding:
- Pulsed Laser Welding Machine: Pulsed laser welding machines are commonly divided into jewelry spot welding machines and mold welding machines.
- Continuous Laser Welding Machine:The common types of continuous laser welding machines can be divided into air-cooled handheld laser welding machines and water-cooled handheld laser welding machines. They can also be classified as industrial robot laser welding machines and collaborative robot laser welding machines.
- Air-cooled handheld laser welding machines, available on the market, do not require the constraints of a chiller. The weight and size of handheld welding machines are reduced, making them more convenient for transportation. However, the stability of air-cooled handheld welding machines for long-duration welding still needs further validation.
- Water-cooled handheld laser welding machines, on the other hand, are capable of adapting to a wider range of welding scenarios. Compared to air-cooled handheld welding machines, they have stronger heat dissipation capabilities and higher efficiency in continuous welding. Currently, water-cooled handheld welding machines remain the primary choice for laser welding users.
- Industrial robot laser welding machine: Industrial robot laser welding machines are primarily suitable for batch production of stainless steel, carbon steel, aluminum alloys, galvanized sheets, and other materials with a thickness range of 0.6-5mm. They are used in industries such as housing cabinets, hardware, furniture, lighting, railing doors and windows, new energy, electromechanical products, etc. The advantages include labor-saving, continuous operation of the machine, improved efficiency, reduced polishing, 2-5 times faster speed, greater flexibility with six axes allowing welding from different angles (e.g., pipes, electric motorcycles, furniture), and simultaneous welding with two robots for large-sized products. They are also cost-effective for welding precision products with seamless or small-seam sheet metal parts.
- Collaborative robot laser welding machine: In many cases, there are various requirements that need assistance from robotic arms. Therefore, robot collaborative handheld welding machines have been developed. Removing the gun head allows it to be used as a conventional handheld welding machine, while attaching it to the robotic arm transforms it into a semi-automatic welding machine. The advantage is that it can be moved by drag-and-drop or handle programming, reducing the long-term pressure on employees holding welding guns or replacing employees in relatively dangerous areas to complete welding operations. Compared to industrial robot systems, collaborative robot welding machines have lower payload capacity and lower welding precision.
1. What materials can be welded with a handheld laser welding machine?
A fiber laser handheld welding machine, depending on the selected power, can weld metal materials such as stainless steel, galvanized sheet, tinplate, iron sheet, brass, and aluminum with a thickness ranging from 0.4mm to 8.0mm. The higher the power, the stronger the welding capability.
2.Can laser welding use wire feeding?
Although laser welding does not require a wire feeder to provide welding wire, in certain special cases, other methods can be used to assist the laser welding process. Welding machines can be equipped with an automatic wire feeder.
3.Does laser welding require shielding gas? What are the specific choices for shielding gas during the welding process?
The common choices are nitrogen or argon. For welding stainless steel, it is recommended to use nitrogen as it provides better welding results. Avoid using mixed or nitrous oxide gases.
4.What are the consumables for handheld laser welding?
The consumables for handheld laser welding include welding nozzles and protective lenses. The specific consumption depends on the frequency of use and continuous operation time.
5.What precautions should be taken during the use of handheld laser welding?
- Ensure safety precautions: Laser welding is a high-energy laser process, so appropriate safety measures must be taken. Ensure proper personal protective equipment is worn, such as laser safety goggles, protective gloves, and protective clothing. Avoid direct exposure to the laser beam to prevent potential eye and skin injuries.
- Maintain good ventilation: Laser welding produces smoke and harmful gases, so ensure the work environment has a good ventilation system to effectively remove exhaust fumes and smoke. If necessary, use exhaust equipment or exhaust hoods to control air quality.
- Familiarize yourself with equipment operation: Before using the handheld laser welding equipment, carefully read and comply with the operation manual and safety guidelines provided by the manufacturer. Familiarize yourself with the normal operating procedures, control buttons, and emergency shutdown devices to ensure proper equipment operation.
- Regularly maintain the equipment: Regularly inspect and maintain the handheld laser welding equipment to ensure its proper functioning. Keep the equipment clean and perform maintenance and servicing as recommended by the manufacturer.
- Prevent reflection and scattering: During laser welding, the laser beam may be reflected or scattered by the surface of the material, leading to unintended injuries. Ensure that the work area does not have surfaces that can reflect or scatter the laser beam and take appropriate shielding measures, such as using laser protective screens or reflection protective covers.
- Maintain proper operating posture: Maintain the correct posture and stable operating technique to ensure the accuracy and safety of the welding process. Avoid direct exposure of the laser beam to yourself or others’ body parts.
Handheld laser welding is currently limited to welding thin sheets due to power constraints. However, future advancements are expected to enable the expansion of laser welding into the realm of thick plates, accompanied by an increase in laser power. It is important to note that high-power lasers can be hazardous to the skin and eyes of operators. Therefore, as welding machines with higher power become prevalent, it will be crucial to enhance employee protection measures and employ additional assistance such as cantilever systems and robotic arms.
