Welding is a vital processing technology in sheet metal fabrication, known for its high labor intensity, challenging working conditions, and the need for skilled operators. As the industry advances, the focus has shifted toward automation and innovative welding methods, with effective quality and efficiency control being paramount. This transition addresses various challenges, including arc stability, weld alignment, and thermal deformation. The introduction of laser welding technology has transformed the field, offering significant advantages across various sectors such as household appliances, high-tech electronics, automobile manufacturing, and precision engineering. A notable advancement is the Handheld Laser Welding Machine, which exemplifies the move toward more flexible and efficient welding solutions. This technology not only enhances traditional welding practices but also significantly improves precision and productivity, marking a pivotal moment in the evolution of welding techniques.
Characteristics of Laser Welding
Laser welding employs a laser to deliver a high-energy laser beam through an artificial fiber. Once transmitted, the beam is collimated into parallel light by a lens and then focused onto the workpiece, creating a highly concentrated heat source. This melts the material at the joint, which then cools rapidly to form a high-quality weld seam.
Simple and Easy to Learn
Laser welding equipment features a straightforward structure, making the operation easy to learn and quick to start. The professional requirements for welding operators are not high, which significantly reduces labor costs.
Capable of Micro Welding
After focusing, the laser beam can achieve a very small spot and precise positioning, making it suitable for the assembly welding of micro and small workpieces in large-scale automated production.
High Flexibility
Laser welding machines can perform welding at any angle, weld hard-to-reach parts, and handle various complex workpieces, including irregularly shaped large components, achieving high flexibility.
Good Welding Effect
The surface of parts welded with lasers is smooth, eliminating the need for grinding. There are no black edges, welding scars, pores, cracks, undercuts, or subsidence defects. The appearance of the weld seam is more aesthetically pleasing and smoother compared to conventional MIG welding and argon arc welding.
Strong Safety Performance
The high-safety welding nozzle activates the switch only when it contacts metal. The touch switch includes body temperature sensing. The specific laser generator has safety requirements during operation, and operators are required to wear protective glasses to reduce the risk of eye damage.
High Laser Quality
After focusing, the laser exhibits high power density. The focused high-power low-order mode laser has a small spot diameter, greatly facilitating the development of thin sheet automated welding.
Fast Welding Speed, Large Depth, and Minimal Deformation
Laser welding has a high power density. During the welding process, a small hole forms in the metal material, allowing laser energy to penetrate deep into the workpiece with minimal lateral diffusion. The depth of material fusion during the laser beam scanning process is significant, with fast speed and a large welding area per unit time.
Low Manual Welding Cost
The heat input in laser welding is extremely low, resulting in minimal deformation after welding, very little welding slag, and no spatter, achieving a beautiful surface finish. Reduced post-processing after laser welding can lower or eliminate the labor costs associated with subsequent polishing and leveling.
Welding Difficult-to-Weld Materials
Laser welding can effectively handle various dissimilar metals, including titanium, nickel, zinc, copper, aluminum, chromium, saw, gold, silver, and their alloys, as well as Kovar alloy. This capability meets the development and application needs of new materials for household products.
Suitable for Welding Thin Non-Coated Appearance Parts
Laser welding machines feature a large aspect ratio, small energy ratio, and a minimal heat-affected zone. The welding deformation is minimal, making them particularly suitable for welding thin non-coated appearance parts and precision heat-sensitive components, reducing post-weld corrections and secondary processing.
Comparison of Laser Welding Advantages
Based on the characteristics of weld seam formation during welding, laser welding can be categorized into heat conduction welding and laser deep penetration welding. Heat conduction welding utilizes low laser power, resulting in longer molten pool formation time and shallow penetration, primarily for small parts welding. Deep penetration welding involves high power density, where metal in the laser radiation area melts rapidly, and intense vaporization occurs simultaneously, resulting in weld seams with greater depth. The weld seam width ratio can reach 10:1. Fiber-transmitted laser welding machines are equipped with CCD camera monitoring systems for easy observation and precise positioning; their welding spot energy distribution is uniform, providing the optimal spot required for welding characteristics. These machines are suitable for various complex weld seams, spot welding, full welding of various devices, and seam welding of thin plates within 1mm.
The main factors affecting laser welding include beam characteristics, welding characteristics, shielding gas, material characteristics, and welding performance:
- Beam characteristics include the laser and optical configuration.
- Welding characteristics involve the form of the welding joint, weld seam distribution, assembly accuracy, and welding process parameters.
- Shielding gas encompasses the type, flow rate, and shielding strength of the gas.
- Material characteristics relate to the wavelength of the laser, material properties, temperature, and surface conditions. Most materials have higher absorption rates for short-wavelength lasers, lower rates at room temperature, and a sharp increase in absorption as temperature rises.
- Material welding performance includes thermal conductivity, thermal expansion coefficient, melting point, boiling point, and other characteristics.
Compared to traditional manual argon arc welding or gas-protected welding, laser welding employs the latest generation of fiber lasers equipped with independently developed welding heads, offering advantages such as easy operation, aesthetically pleasing weld seams, fast welding speed, and no consumables. It can effectively replace traditional argon arc welding, electric welding, and other processes for welding stainless steel plates, iron plates, galvanized plates, aluminum plates, and other metals.
There are several common welding methods for thin plates, including laser welding, electron beam welding, argon arc welding, resistance welding, and plasma arc welding. Compared to other common welding methods, laser welding has significant advantages in terms of heat-affected zone, depth ratio, weld seam cross-sectional morphology, ease of operation, automated processing, labor costs, and more.
Laser Welding Process Parameter Settings
The key to laser welding equipment lies in the setting and adjustment of process parameters. Depending on the thickness and material of the parts, different scanning speeds, widths, power values, etc., should be selected (the duty cycle and pulse frequency usually do not need to be changed).
- The process interface includes adjustable process parameters. Click the box to modify, and click OK after making changes, then save it in the quick process. When in use, click import.
- The scanning speed range is 2 to 6000 mm/s, and the scanning width range is 0 to 5 mm. The scanning speed is limited by the scanning width, with the relationship being: 10 ≤ scanning speed (scanning width × 2) ≤ 1000. If the limit is exceeded, it will automatically revert to the extreme value. When the scan width is set to 0, it will not scan (i.e., point light source) (the most commonly used scan speed is 300 mm/s, width 2.5 mm).
- Peak power should be less than or equal to the laser power on the parameter page.
- Duty cycle range is 0 to 100 (default is 100, usually does not need to be changed).
- Pulse frequency range is recommended to be 5 to 5000 Hz (default is 2000, usually does not need to be changed).
The welding power varies with different material thicknesses and types, and the laser power is the maximum power of the laser used. When the laser is activated, the output starts from the initial process power and gradually increases to 100%. When the laser is turned off, it gradually decreases from 100% of the process power to the power-off level.
Selection Guide for Laser Welding Machines
When choosing a laser welding machine, it is essential to consider factors such as the type of welding required, the specific materials to be welded, and the features of the machine. Here are some reputable brands that offer high-quality laser welding products, including the notable ADH brand.
1. ADH Machine Tool
ADH has established itself as a leader in the field of laser welding technology, known for its innovative solutions and advanced machinery. Their Handheld Laser Welding Machine is particularly praised for its flexibility and ease of use, making it suitable for a variety of applications, from small-scale assembly to more complex welding tasks. ADH machines are built with safety features and offer high welding speeds while delivering immaculate weld seams without the need for extensive post-weld processing.
2. Trumpf
Trumpf is a globally recognized brand offering a broad range of laser welding systems. Their machines are renowned for precision engineering and reliable performance. The TruLaser Series includes various models tailored for different welding needs, ensuring that users can find a solution that meets their specific requirements. Trumpf’s robust software integration allows for efficient automation in welding processes.
3. IPG Photonics
Known for their cutting-edge fiber laser technology, IPG Photonics specializes in high-performance laser systems that provide exceptional results in welding applications. Their products are especially suited for high-volume manufacturing environments due to their speed and efficiency. The YLR Series lasers are particularly well-regarded for their high efficiency and power, making them ideal for intricate welding tasks.
4. Kawasaki Robotics
Kawasaki is not only a leader in robotics but also offers advanced laser welding solutions, particularly for automated applications. Their laser welding robots are designed for high-efficiency production lines, providing superior accuracy and repeatability. The integrated systems allow for seamless operation in diverse industrial settings.
Key Considerations When Choosing a Brand:
- Application Requirements: Determine what types of materials and thicknesses you will be welding, as different machines excel in different areas.
- Safety Features: Look for models equipped with necessary safety functions, such as protective nozzles and eye protection.
- Support and Service: Evaluate the brand’s reputation for customer service and technical support, as well as availability of spare parts.
- User Reviews: Research user experiences to gauge the reliability and performance of the welding machines from these brands.
Conclusion
Today, almost all fields, including machinery manufacturing, petrochemicals, transportation energy, metallurgy, electronics, aerospace, and others, rely on welding technology. The new generation of welding technology, represented by electron beam welding and laser welding, is increasingly being applied. Considering environmental protection and operational costs, laser welding offers numerous advantages, including high power density, no electrode contamination, non-contact operation, minimal tool wear, and immunity to magnetic fields, allowing for precise alignment of the weld seam. Therefore, laser welding represents the future trend in welding, necessitating that technical personnel in enterprises establish better and higher application standards to collectively drive the advancement of laser welding machine companies.