What is Laser Welding? Laser Welding vs. Traditional Welding

Laser welding can sound like something out of a sci-fi movie, but it is actually a commonly used method in industrial manufacturing. It involves using a high-powered laser to melt and fuse materials together, creating a strong bond without the need for additional filler material. This process is often compared to traditional welding techniques, but there are some significant differences between the two. In this post, we will discuss what laser welding is and how it’s different from traditional welding methods.

What is Laser Welding?

Laser welding is a high-precision process that uses a focused laser beam to join materials. The basic principle behind laser welding is the concentration of light energy into a small, intense spot, creating enough heat to melt and fuse the materials together.

Laser welding was first developed in the 1960s and has since become a popular method for joining materials such as metals, plastics, and polymers. Many industries, including automotive, aerospace, and medical device manufacturing, use laser welding for its precision and efficiency.

How Does Laser Welding Work?

So, how does laser welding actually work? At the heart of laser welding is a laser, which stands for “Light Amplification by Stimulated Emission of Radiation.” The laser generates an intense beam of coherent light. This light is concentrated into a narrow, high-energy beam, which can reach extremely high temperatures, often in the range of several thousand degrees Celsius.

The laser beam is focused using a series of optics, such as lenses or mirrors, to a precise point. The beam’s spot size can be adjusted based on the type of material and the desired welding depth. The smaller the spot, the more concentrated the energy.

When the focused laser beam strikes the surface of the material, the energy from the laser is absorbed by the material, causing rapid heating. For metals, this energy absorption causes the surface to melt quickly.

Different materials have varying absorption levels, depending on factors such as their reflectivity and thermal conductivity. Highly reflective metals like aluminum and copper require lasers with particular wavelengths for efficient energy absorption.

Once the material has been melted and the laser beam is removed, the molten metal cools and solidifies, forming a welded joint. The high energy of the laser allows for rapid cooling, resulting in a strong bond between the pieces of material.

Types of Laser Welding

There are many different types of laser welding processes, each with pros and cons. Depending on the job requirements, a certain type of laser welding may be best.

• Conduction Welding: This is the most commonly used type of laser welding, where the heat from the laser beam is conducted through the material to cause melting and bonding. It is ideal for thin materials and creates highly precise welds with minimal distortion.
• Keyhole Welding: In this process, high energy density from the laser beam melts a hole in the material before it is filled with molten metal from the edges. The resulting welds are strong and can penetrate deep into thick materials.
• Hybrid Welding: As the name suggests, this process combines laser welding with other traditional methods, such as gas metal arc welding (GMAW) or tungsten inert gas (TIG) welding. This allows for more flexibility and control in the welding process and can be used to weld a wider range of materials.
• Fiber Laser Welding: This type of laser welding uses a fiber optic cable to deliver the laser beam, allowing for more precise control over the welding process. It is often used in high-speed or automated welding applications.

These are only a few examples of the many types of laser welding available. Other processes include pulsed laser welding and continuous wave laser welding. The type of laser welding used will depend on the material being welded and other factors such as time and budget constraints.

Laser Welding vs. Traditional Welding

To help understand how laser welding stacks up against traditional welding methods, let’s break down each key aspect—precision, speed, cost, materials, and applications.

1. Precision:
2. Laser Welding: Offers extremely focused energy, allowing for precise, small, and clean welds. Ideal for fine work in electronics, medical devices, and thin metals.
3. Traditional Welding: Moderate precision, with wider welds. TIG welding is the most precise among traditional methods, commonly used in aerospace and automotive.
4. Speed:
5. Laser Welding: Operates at very high speeds, making it suitable for mass production and automated processes.
6. Traditional Welding: Slower, especially for precise or thick materials. MIG welding is faster but not as quick as laser welding.
7. Heat-Affected Zone (HAZ)
8. Laser Welding: Produces a small HAZ, reducing the risk of warping, distortion, and material weakening.
9. Traditional Welding: Creates a larger HAZ, which can lead to material distortion and weakening, especially on thin metals.
10. Penetration Depth
11. Laser Welding: Can achieve deep penetration with minimal weld width, making it ideal for thick and hard-to-reach joints.
12. Traditional Welding: Penetration depth depends on the method. Arc welding can achieve deep penetration but with more heat spread.
13. Weld Quality (Aesthetics)
14. Laser Welding: Produces clean, smooth, aesthetically pleasing welds with minimal post-processing required.
15. Traditional Welding: Welds are often rougher and require grinding or polishing to achieve a smooth finish.
16. Portability
17. Laser Welding: Systems are often large and require stable environments, limiting portability.
18. Traditional Welding: Portable, especially arc and stick welding, making them suitable for fieldwork and construction.
19. Initial Investment Cost
20. Laser Welding: High initial cost due to expensive equipment and maintenance (laser generators, cooling systems, optics).
21. Traditional Welding: Lower initial cost, with more affordable equipment and less expensive maintenance.
22. Operating Cost
23. Laser Welding: While energy-efficient, it requires specialized training and expensive maintenance, which can increase costs.
24. Traditional Welding: Lower operating costs, as equipment is cheaper to maintain and training is widely available.
25. Flexibility and Versatility
26. Laser Welding: Suitable for a range of materials and applications but is limited by material thickness and equipment size.
27. Traditional Welding: Highly versatile, capable of working in various environments (indoor, outdoor, undersea) and on different material thicknesses.
28. Safety Concerns
29. Laser Welding: Generally safer, with less exposure to fumes and spatter, though laser light requires proper eye protection.
30. Traditional Welding: Requires significant safety precautions due to UV radiation, fumes, sparks, and molten metal exposure.

Laser welding and traditional welding each have their place in the metalworking industry. Considering the needs and constraints of a specific project will help determine which method is best suited for the job. For example, if a project requires precision and minimal distortion, laser welding may be the better choice. However, if portability and cost-effectiveness are important factors, traditional welding may be best.

Learn More About Laser Welding or Get High-Quality Pipe Fitting Tools with H&K Fabrication

We hope this post has given you a better understanding of laser welding and how it differs from traditional methods. Expanding the number of welding techniques you are familiar with can help you improve your skills and offer more diverse services. At H&K Fabrication, we are dedicated to providing high-quality pipe-fitting tools and equipment for all types of welding methods, including laser welding. Visit our website or contact us today to learn more!