Laser welding is a process that uses a focused beam of light to join two or more materials together. It has many advantages over conventional welding methods, such as high speed, precision, low heat input, and minimal distortion. Laser welding is widely used in various industries, such as aerospace, medical, electronics, and jewelry. However, one of the most prominent and growing applications of laser welding is in the automotive industry, where it is used to manufacture and assemble various components and parts of vehicles.
In this article, we will explore the types of industrial laser welders, the applications of laser welding in automotive welding, and the trends and challenges that affect the future of this technology.
I. Types of Industrial Laser Welders
Two main types of industrial laser welders are used for automotive welding: CO2 lasers and Nd: YAG lasers. These lasers have different characteristics and advantages, depending on the application and the material to be welded.
1) CO2 Lasers
CO2 lasers are gas lasers that emit infrared light at a wavelength of 10.6 micrometers. They are excited by an electric discharge and can produce high power output, up to 60 kW. CO2 lasers are mainly used for welding thick metal sheets and tubes, such as steel, aluminum, and titanium. They have a high efficiency, a good beam quality, and a low operating cost. However, they require polished mirrors to transmit the beam, which can be damaged by dust and debris. They also have limited flexibility in beam delivery, as they cannot bend or split the beam easily.
2) Nd: YAG Lasers
Nd: YAG lasers are solid-state lasers that emit near-infrared light at a wavelength of 1.06 micrometers. They are pumped by flashlamps or diodes and can produce moderate power output, up to 4 kW. Nd: YAG lasers are mainly used for welding thin metal sheets and wires, such as copper, brass, and gold. They have a high flexibility in beam delivery, as they can use fiber optic cables to transmit the beam, which can bend and split the beam into multiple beams. They also have a high accuracy and a small spot size, which enable precise and intricate welding. However, they have a low efficiency, poor beam quality, and a high operating cost. They also require cooling systems to prevent overheating.
II. Applications of Laser Welding in Automotive Welding
Laser welding has a wide range of applications in automotive welding, from large-scale welding of body frames to small-scale welding of electronic components. Some of the common and emerging applications are:
1) Body-in-White Welding
Body-in-white (BIW) is the term used to describe the welded metal body of a vehicle before painting and assembly. It consists of various parts, such as door frames, trunks, hoods, and chassis, that are joined together by welding. Laser welding is one of the preferred methods for BIW welding, as it offers high speed, high strength, and low distortion. Laser welding can also reduce the weight and the number of parts of the BIW, which can improve the fuel efficiency and the performance of the vehicle. CO2 lasers are typically used for BIW welding, as they can weld thick metal sheets and tubes with high power and low heat input. However, Nd: YAG lasers are also gaining popularity, as they can weld thin metal sheets and wires with high flexibility and accuracy.
2) Tailored Blank Welding
Tailored blanks are metal sheets that have different thicknesses, grades, or coatings, that are welded together to form a single sheet. They are used to create customized parts that have specific properties, such as strength, stiffness, or corrosion resistance, for different regions of the vehicle. For example, a tailored blank can have a thicker and stronger metal in the middle and a thinner and lighter metal on the edges, which can reduce the weight and increase the safety of the part. Laser welding is the most common method for tailored blank welding, as it can weld different metals with high speed and quality. CO2 lasers are usually used for tailored blank welding, as they can weld thick and dissimilar metals with high power and low heat input.
3) Plastic Welding
Plastic welding is the process of joining plastic parts together by heating and melting them. It is used to create various components of the vehicle, such as front and back lights, bumpers, dashboards, and electronic housings. Laser welding is one of the advanced methods for plastic welding, as it can weld complex and delicate shapes with high precision and quality. Laser welding can also create invisible welds, which can improve the appearance and the design of the plastic parts. Nd: YAG lasers are mainly used for plastic welding, as they can weld thin and transparent plastics with high flexibility and accuracy. However, CO2 lasers can also be used for plastic welding, if the plastics are coated with an infrared-absorbing material.
4) Electronic Component Welding
Electronic component welding is the process of joining electronic parts together by creating electrical connections. It is used to create various devices and circuits that are essential for the functioning and performance of the vehicle, such as airbag initiators, motor coil windings, battery tabs, and powertrain connections. Laser welding is one of the preferred methods for electronic component welding, as it can weld small and sensitive parts with high precision and quality. Laser welding can also create reliable and durable connections, which can withstand high temperatures, vibrations, and shocks. Nd: YAG lasers are predominantly used for electronic component welding, as they can weld thin and conductive metals with high flexibility and accuracy.
III. Trends and Challenges of Laser Welding in Automotive Welding
Laser welding is a rapidly evolving technology that is influenced by various trends and challenges in the automotive industry. Some of the major factors that affect the future of laser welding are:
1) Vehicle Electrification
Vehicle electrification is the trend of replacing conventional internal combustion engines with electric motors and batteries. It is driven by the increasing demand for environmentally friendly and energy-efficient vehicles. Vehicle electrification poses new opportunities and challenges for laser welding, as it requires the welding of new materials and components, such as electric motor components, battery cells, and modules, and power electronics. Laser welding can offer high speed, quality, and reliability for these applications, but it also faces some difficulties, such as welding of dissimilar and reflective metals, welding of thin and fragile parts, and welding of large and complex assemblies.
2) Material Innovation
Material innovation is the trend of developing and using new materials that have superior properties, such as strength, stiffness, weight, and corrosion resistance. It is driven by the increasing demand for lightweight and high-performance vehicles. Material innovation creates new possibilities and challenges for laser welding, as it requires the welding of new combinations and grades of metals and plastics, such as high-strength steels, aluminum alloys, and carbon fiber-reinforced plastics. Laser welding can offer high power, quality, and flexibility for these applications, but it also faces some problems, such as welding of heterogeneous and coated materials, welding of thin and thick materials, and welding of heat-sensitive and distortion-prone materials.
3) Process Automation
Process automation is the trend of using machines and software to perform and control the welding process. It is driven by the increasing demand for high productivity and quality in the automotive industry. Process automation enhances the capabilities and the efficiency of laser welding, as it enables high speed, accuracy, and consistency for the welding process. Process automation also reduces human intervention and errors in the welding process, which can improve the safety and the cost of the welding process. However, process automation also requires high investment and maintenance for the laser welding equipment and systems, which can increase the complexity and the risk of the welding process.
IV. Conclusion
Laser welding is a powerful and versatile technology that has many applications and benefits in the automotive industry. It can weld various materials and components of vehicles with high speed, precision, quality, and reliability. It can also reduce the weight and the number of parts of vehicles, which can improve the fuel efficiency and the performance of vehicles. However, laser welding also faces some challenges and limitations, such as welding of new and dissimilar materials, welding of thin and fragile parts, and welding of large and complex assemblies. Laser welding also requires high investment and maintenance for the equipment and systems, which can increase the complexity and the risk of the welding process. Therefore, laser welding needs to be constantly developed and improved to meet the changing and demanding needs of the automotive industry.
