Laser Beam Welding (LBW) or Laser Welding is one of the welding processes of modern times. It joins pieces of metal using a laser beam. To master this welding process, individuals need to practice and get evaluated by seniors. Many employers require certification for performing certain beam welding jobs. Laser welding is employed in various manufacturing industries. So, let us dive into the details of Laser beam welding (LBW).
Post Highlights:
- What is Laser Beam Welding?
- Laser Beam Welding Principle
- Laser Beam Welding Diagram
- Laser Beam Welding Symbols
- Laser Beam Welding Parameters
- Laser Beam Welding Equipment
- Laser Beam Welding Techniques
- Types of Laser Beam Welding
- Laser Beam Welding Certification
- Laser Beam Welding Handbook
- Applications of Laser Beam Welding
- Advantages of Laser Beam Welding
- Disadvantages of Laser Beam Welding
- Laser Beam Welding vs Electron Beam Welding
- Laser Welding Employment Areas
- Laser Welding Job Types
- Laser Welding Salary Trends
What is Laser Beam Welding?
Laser beam welding or laser welding is a high-precision welding technique. The process uses a focused beam of laser light to join materials. During the process, a laser beam is directed at the workpiece. As a result, it heats the material to the melting point and then fuses it together with the adjacent material.
CO2, Nd:YAG or fiber laser produces a concentrated beam of light energy in form of a laser beam. These lasers are capable of producing a high-intensity, and narrow beam of light. This beam can focus on very small spot sizes and enables precise control of the heat input and welding process.
Laser Beam Welding Principle
Principle-
The LBW principle states that laser light can be concentrated and focused to a very small spot size (ranging from a few tenths of a millimeter to a few millimeters in diameter). The concentrated beam of light energy has a high power density. This means it can deliver a large amount of energy to a small area in a very short period of time.
As the laser beam is focused on the workpiece, then the material absorbs the energy of the laser light and rapidly heats up to its melting point. Further, the melted material then solidifies to form a strong bond between the two pieces being joined.
Laser welding can be performed in either a pulsed or continuous mode. This depends on the required weld quality and the material being welded. Normally, LBW pulsed mode is used for welding thin materials, and LBW continuous mode is for thicker materials.
Overall, the principle is based on the precise control of the laser beam to deliver a controlled amount of energy to the workpiece.
Laser Beam Welding Diagram
The diagram of laser welding is as follows-
In the diagram, the workpiece is positioned under the laser beam. Next, it is directed onto the area where the weld is to be created. The laser beam heats the workpiece, causing it to melt. This forms a pool of molten material in the weld region. As the laser beam moves along the joint, the molten material solidifies and forms a strong weld. Typically, the weld region is a narrow strip.
The operator must control the laser beam and ensures that the energy input is just enough to melt the material without causing excessive heat input or distortion.
Laser Beam Welding Symbols
The LBW symbols provide information about the shape, size, joint orientation, welding process, and other parameters. The symbols are typically used on engineering drawings and specifications to provide clear information about the welding requirements.
Some common laser beam welding symbols are as follows.
1. Circle – This indicates the location of the weld. The arrow points to the area where the weld will start.
2. Straight Line or Series of Lines – This indicates the extent of the weld. Also, the length of the line represents the length of the weld.
3. Checkmark – This indicates the method of welding. In LBW, the symbol looks like two intersecting lines with a small circle at the intersection.
4. Number Inside Weld Symbol – This indicates the weld size (in millimeters).
5. Triangle – This indicates the weld preparation. But this symbol is not used in LBW as the process does not require a specific weld preparation.
6. Letter “F” Weld Symbol – This indicates the welding process. For laser beam welding, the letter “L” is used instead.
7. Others – There may be other symbols used to indicate additional welding parameters, such as the power density, welding speed, or shielding gas.
Laser Beam Welding Parameters
Some of the most important LBW parameters are as follows.
1. Beam Diameter – This is the size of the laser beam and it focuses on the workpiece. This affects the power density and also can affect the welding speed and penetration. Smaller beam diameter results in higher power densities and faster welding speeds.
2. Focal Position – This is the focal point of the laser beam relative to the workpiece. This affects the power density and depth of penetration and can affect the quality of the weld as well. A too-far focal point from the workpiece can result in poor penetration. And a focal point that is too close can result in excessive heat input and distortion.
3. Laser Power – This is the amount of energy the laser beam delivers to the workpiece per unit of time. This parameter affects the heat input. Further, it can also affect the depth of penetration and the overall weld quality. The higher laser power can result in deeper penetration. But it can also increase the risk of defects.
4. Pulse Frequency – This is the rate at which the laser beam is pulsed on and off. This affects the heat input and the quality of the weld. The higher pulse frequencies can result in higher productivity. But it can also reduce penetration and quality.
5. Shielding Gas – It is a gas that protects the weld from contamination and oxidation. This parameter affects weld quality by preventing the formation of defects (porosity). Commonly, argon and helium are used as shielding gases used in laser welding.
6. Welding Speed – This is the speed at which the laser beam moves along the joint. The parameter affects the heat input and can affect the weld quality. Faster welding speeds can result in higher productivity. But it can also reduce penetration and quality.
Laser Beam Welding Equipment
Some of the main components of a laser welding system include-
1. Beam Delivery System – This consists of lenses and mirrors that are used to direct and focus the laser beam onto the workpiece. This system is typically mounted on a robotic arm or a CNC system. It allows for precise control over the welding process.
2. Control System – This includes hardware and software that are used to control the beam delivery system, laser source, and other components of the LBW system. This system allows for precise control over the welding process, including the welding speed, laser power, and other parameters.
3. Cooling System – This is typically used to maintain a stable temperature and prevent damage. Because laser welding generates a significant amount of heat and can damage the laser source and other components of the system.
4. Laser Source – This device generates the laser beam. LBW can use several types of laser sources such as Nd:YAG, CO2, and fiber lasers. The material being welded and the required welding parameters decide the type of laser source used.
5. Workpiece Fixturing – This device holds the workpiece in place during welding. The fixturing setup must provide a stable and accurate location for the workpiece. This ensures that the weld is produced to the required specifications.
6. Safety Features – Laster welding can be hazardous if proper safety precautions are not followed. The safety features of a typical LBW system include shielding, warning lights, and interlocks to protect operators and bystanders from the laser beam.
Laser Beam Welding Techniques
Some of the most common laser welding techniques are as follows.
1. Conduction Welding – In this type, the laser beam is focused on the workpiece, and the heat is conducted through the material to melt and fuse the joint. This technique is suitable for welding thin materials with low melting points (copper, aluminum).
2. Laser Brazing – Here, a laser beam is used to heat the workpiece and the filler material simultaneously. Consequently, it creates a strong bond between the two materials. This technique is employed to join materials using filler material, such as silver or copper.
3. Deep Penetration Welding – In this type, the laser beam focuses on a small spot size and moves along the joint at a slow speed. The high-power density of the beam creates a keyhole that penetrates deeply into the material. Subsequently, it imparts a strong weld. This technique is suitable for welding thicker materials and producing deeper welds.
4. Percussion Welding – In this welding, the laser beam is pulsed at a high frequency to rapidly melt and fuse the materials together. The technique good option for welding materials with different thermal properties and melting points. It can be used for welding dissimilar materials, such as steel and aluminum.
5. Hybrid Welding – Typically, this technique combines laser beam welding with another welding process like GMAW and GTAW. This way can improve the efficiency and quality of the welding process by combining the advantages of both processes.
Types of Laser Beam Welding
Some of the most common types of laser welding are as follows.
1. CO2 Laser Welding – This technique uses a carbon dioxide (CO2) laser to generate the laser beam. Because CO2 lasers are efficient and produce a high-power beam. This can be used to weld a wide range of materials, including metals, ceramics, and plastics.
2. Continuous Wave Laser Welding – This technique uses a laser beam that is continuously emitted to create a continuous weld along the joint. This welding type is useful for welding thicker materials and for producing high-quality and strong welds.
3. Fiber Laser Welding – The technique uses a fiber optic cable to deliver the laser beam to the workpiece. Fiber lasers are highly efficient and can produce a high-quality beam. This is suitable for welding metals and other materials.
4. Nd:YAG Laser Welding – This one uses a neodymium-doped yttrium aluminum garnet (Nd:YAG) laser to generate the laser beam. Nd:YAG lasers can produce a high-quality beam and a good fit for welding thin materials, such as sheet metal.
5. Pulsed Laser Welding – The welding type uses a laser beam that is pulsed at a high frequency to create small, and controlled welds. This technique is suitable for producing complex geometries and for welding materials with different thermal properties.
6. Remote Laser Welding – This technique uses mirrors and other optical components for the laser beam and delivers it to the workpiece. This welding type is well-suited for welding parts that require a high degree of precision and are difficult to access.
Laser Beam Welding Certification
Laser welding certification is a process that verifies an individual’s knowledge, skills, and ability to perform LBW operations safely and effectively. Usually, educational institutions, professional organizations, or industry associations offer Certifications. Individuals typically need to complete a combination of education, training, and testing requirements.
The requirements may include –
1. Complete LBW Training Program – This may include the completion of a formal training program at a technical school or community college, or participating in an apprenticeship or on-the-job training program.
2. Obtain Hands-on Experience – Work experience is necessary to demonstrate the ability to perform LBW operations safely and effectively in a supervised setting.
3. Pass Certification Exam – The exam may include written and practical. It typically covers topics such as welding procedures, welding safety, quality control, LBW principles, and techniques.
4. Maintaining Certification – To maintain LBW certification, individuals may need to participate in periodic recertification exams, complete continuing education requirements, or meet other requirements established by the certifying organization/authority.
LBW Certification can be an important credential for welders, particularly those who are seeking employment with large manufacturing companies or government agencies.
Laser Beam Welding Handbook
Different organizations and authors publish handbooks on laser beam welding (LBW). Some LBW handbooks commonly used as references in the welding industry are as follows.
1. Laser Welding: Core Research from TWI by P. Hilton, P. Colegrove, and A. Dowden. It provides an overview of research on laser welding conducted by The Welding Institute (TWI). It covers topics such as laser beam characterization, process modeling, and defect analysis.
2. Laser Welding: A Practical Guide by Hans W. Bergmann and Jorg Hermsdorf. It provides a comprehensive overview of laser welding techniques, principles, and applications with a focus on practical considerations and case studies.
3. Handbook of Laser Welding Technologies by S.K. Mazumder and John K. Chen. It covers a wide range of laser welding technologies, including solid-state, gas, and fiber lasers, and applications in industries such as automotive, aerospace, and electronics.
4. Laser Welding and Joining of Advanced Materials by Mahesh Chaturvedi and Yuriy S. Solyaev – This focuses on laser welding of advanced materials, including high-strength alloys, composites, and ceramics. It covers topics such as quality control, process modeling, and automation.
5. Laser Welding of Plastics by Gunter K. Janben and Guido P. Steenblik – This focuses specifically on the laser welding of plastics, covering topics such as quality control, material selection, equipment, and process parameters.
These LBW handbooks are just a few examples of the many resources available to welders, engineers, technicians, and other professionals involved in LBW operations.
Applications of Laser Beam Welding
Some of the common applications of LBW are as follows.
1. Automotive Industry – LBW is used here to join parts made from high-strength steel, aluminum, and other materials. The most common use of laser welding is in the production of suspension components, chassis, and exhaust systems.
2. Aerospace Industry – The industry used LBW to join lightweight, complex structures made from titanium, aluminum, and other alloys. The common uses are the production of engine components, aircraft fuselages, and other critical parts.
3. Electronics Industry – The use of laser welding here is to join delicate, small parts made from plastics, metals, and ceramics. The process is most commonly used in the production of circuit boards, microelectronic components, and sensors.
4. Tool/Die Industry – This industry uses LBW to repair and modify dies, molds, and other precision tooling. Also, used to add material to worn or damaged surfaces, and to join dissimilar materials.
5. Medical Industry – This industry uses LBW to join small, precision parts made from titanium, stainless steel, and other materials. The common use is in the production of implants, surgical instruments, and medical devices.
6. Jewelry Industry – This industry employs LBW to join precious metals such as platinum and gold. The main use is to create intricate designs and to join parts with minimal distortion or discoloration.
Laser welding is a flexible and precise welding type that can be used in a wide range of applications and industries.
Advantages of Laser Beam Welding
Some of the main advantages of laser welding are as follows.
1. Automation Process – Laser welding is an automated process and can be easily integrated into manufacturing. This makes it a good option for high-volume production environments.
2. Non-Contact Technique – This means that the laser beam does not physically touch the materials being welded. This minimizes the need for post-weld cleaning and reduces the risk of contamination.
3. Precise/Consistent – The technique is consistent and precise and produces high-quality and precise welds with minimal distortion or discoloration. The process is an ideal choice for joining thin, delicate materials and can be used to produce repeatable results.
4. High-Speed Technique – LBW can join materials efficiently and quickly. This results in leading to increased productivity and lower production costs.
5. Safe Technique – LBW is safe because it produces minimal fumes or emissions. This also reduces the risk of operator injury or fatigue, as it is a non-contact process.
6. Versatility – LBW can be used to weld a wide range of materials such as plastics, metals, and ceramics. This can also be used to join dissimilar materials.
Disadvantages of Laser Beam Welding
Some of the main disadvantages of laser welding are as follows.
1. Operator Training – Performing laser welding requires specialized training and expertise to maintain the equipment. So, this can increase labor costs and makes it challenging for smaller manufacturers to adopt.
2. High Equipment Cost – LBW equipment cost is high compared to other welding types. So, this makes it more expensive for low-volume applications and smaller production runs.
3. Difficult Joint Accessibility – As LBW requires a direct line of sight between the laser and the joint being welded. This can make it difficult to weld joints that are difficult to access (complex or irregularly shaped parts).
4. Material Limitations – Although laser welding can be used for a wide range of materials, it is not suitable for all materials. For example, materials with high reflectivity (copper/aluminum) can be difficult to weld with laser beam welding.
5. Weld Depth Limits – Laser welding is not ideal for producing deep welds or welding thick materials. This limit can strict its usefulness in certain applications.
Despite all this, laser welding remains a popular welding technique in many industries due to its precision, speed, and versatility.
Laser Beam Welding vs Electron Beam Welding
Some of the main differences between LBW and EBW are as follows.
1. Energy Source – LBW uses a laser beam to generate heat and melt the materials being welded. EBW uses an electron beam to achieve the same result.
2. Equipment Cost – LBW equipment is less expensive than EBW equipment. EBW needs vacuum chambers and electron guns.
3. Joint Accessibility – LBW requires a direct line of sight between the laser and the joint being welded. EBW can weld through non-metallic materials and can reach joints that are difficult to access.
4. Material Limitations – LBW can be used to weld a wide range of materials. EBW is a good option for welding metals with good thermal conductivity and high melting points.
5. Weld Depth – LBW has limitations for deep welds. EBW can produce deeper welds due to its higher power density and deeper penetration into the material.
6. Welding Speed – LBW is generally faster due to the higher power density of the laser beam. EBW is less fast than LBW in terms of speed.
Laser Welding Employment Areas
Some of the main employment areas for laser welding are as follows.
- Aerospace Industry
- Automotive Industry
- Electronics Industry
- Jewelry Industry
- Medical Industry
- Military/Defense Industry
- Tool/Die Industry
Laser Welding Job Types
Some of the main job types in laser welding-
- Laser Welding Operator
- Laser Welding Technician
- Quality Control Inspector
- Research/Development Engineer
- Welding Engineer
- Laser Applications Engineer
- Laser Maintenance Technician
- Laser Welder
Laser Welding Salary Trends
The salary for laser welding professionals in the United States is not the same. It depends on various factors such as level of experience, job type, industry, and geographic location.
The average yearly salary of different laser welding professionals is as follows.
- Laser Welding Operator – $30,000 to $60,000
- Laser Welding Technician – $40,000 to $80,000
- Quality Control Inspector – $35,000 to $80,000
- Research/Development Engineer – $70,000 to $140,000
- Welding Engineer – $60,000 to $120,000
This salary figure may vary from place to place depending on several local factors. For example, LBW professionals may earn more in the aerospace industry than those working in the automotive industry.
Summary
Laser Beam Welding (LBW) is a specialized welding technique that imparts high-quality and precise welds. The welding technique is employed in a wide range of applications in industries such as automotive, aerospace, medical devices, electronics, etc. LBW requires special skills and knowledge to perform successfully. The salary trends depend on several factors like education, experience, job type, and industry location. Finally, the above-given information on laser beam welding is crucial and important for different welding professionals working in the welding industry.
