Laser welding is widely used by manufacturers for its incredible precision and versatility, allowing them to fuse materials with minimal distortion. Over the past two decades, advancements in laser technology have made it more accessible and cost-effective.
So, how does laser welding work? Get to know this welding technology in this article.
What is Laser Welding?
Laser welding is the process of combining metal or thermoplastic parts using high-intensity laser beam energy. This welding technique emerged in the early 1960s following the invention of the first-ever laser.
In laser welding, the beam hits a surface with high spot precision which creates a concentrated heat source. This eventually turns into a molten pool that solidifies and enables rapid welding of material parts. With its high-level precision and speed, laser welding ensures little to no material deformation or thermal damage.
Today, laser welding is used extensively in various industries that deal with thin or complex material components such as automotive, aerospace, electronics, and medical industries.
How Does a Laser Welder Work?
The process of laser welding can be broken down into three steps:
- The laser welder (or laser welding machine) emits a laser beam concentrated on a particular spot of the material’s surface.
- The concentrated beam produces heat that is high enough to melt (or even vaporize) the contact point. You can think of it in the same way how the concentrated light from a magnifying lens can induce heat when it focuses on a surface.
- A molten pool is formed on the contact point where the pieces can be pressed and fused together. When this pool is cooled and solidified, the material parts are united.
Types of Laser Welding
Depending on your needs, there are two different approaches to performing laser welding. You can either apply the conduction mode or the keyhole mode laser welding.
Conduction Welding
In conduction welding, the emitted laser beam is at low energy density (around 0.5 MW/cm2) so it slowly melts the metal and forms a wide and shallow weld pool. The relatively “gentler” energy emission leads to uniform heat transfer within the metal.
This type is widely used when aesthetics and details are highly important in the end product.
Keyhole Welding
Also known as penetration welding mode, keyhole welding uses a peak power density of over 1.5MW/cm2. The melting process is very aggressive it rapidly melts and digs the surface. It’s also common for some spots to reach their vaporization temperature in this type of laser welding. Heat transfer in keyhole welding is oftentimes perpendicular to the laser beam.
Keyhole welding is typically used in high-volume production lines due to their need for swift fusion of material components in bulk quantities.
Continuous vs. Pulsed Technology: Choosing the Right Laser for Welding
Selecting the right technology can make all the difference in precision, efficiency, and material integrity. Welders typically choose between two main types: continuous wave (CW) lasers and pulsed lasers.
Continuous Laser Welding
CW lasers produce a steady and sustained beam. They need at least 200 watts of energy and high feed rates to avoid overheating the contact point. This type of laser welding are commonly used in deep penetration of sensitive materials like stainless steel or or ferrous metals.
Pulsed Laser Welding
Pulsed lasers, on the other hand, use “bursts” or pulses of laser energy at a particular width, frequency, and duration. Due to its capacity for high-energy bursts quickly, pulsed lasersare ideal for welding thin and heat-sensitive materials.
Since pulsed lasers emit high energy at the start of a pulse, they are particularly effective on most reflective metals. They can break past the material’s reflectivity at low average power and temperature, so they can’t damage the components within the material.
Advantages and Disadvantages of Laser Welding
To see if laser welding is beneficial to your current production needs, it’s essential to understand its upsides and downsides.
Advantages of Laser Welding
- Less Damage To Surrounding Surfaces: Laser welding’s high-density power emission ensures that the heat is applied to the target spot at high precision. So, you’re guaranteed that the surrounding surface of the parent material won’t suffer from stress or damage.
- High Weld Speed: It’s estimated that laser welding is at least five times faster than the traditional arc welding method. The laser’s higher power intensity leads to improved weld speed as well as quicker production turnaround.
- Impressive Welding Versatility: Whether it’s thick or thin material, laser welding can penetrate them with absolute speed and precision. Even delicate materials like precious jewelry, ceramics, or electronic components can be fused properly with laser welding.
- Eliminates Post-Welding Processes: Laser welding’s controlled and concentrated heat emission ensures seamless fusion of metals without the need for post-welding processes such as grinding. So, the overall welding process becomes faster and more cost-effective.
Disadvantages of Laser Welding
- High Investment Cost: Laser welding requires high initial capital to implement because of the sophisticated technology involved.t’s about three times as expensive as the old-fashioned welding methods. For this reason, many small businesses are reluctant to adopt laser welding as it may take years to gain a return on investment.
- Limitations in Penetration Capabilities: While laser welding excels at combining thin materials, it’s not as effective when dealing with thicker ones. The laser’s penetrative capabilities get weaker as it goes deeper into a thicker material, and it may take time for it to complete the job.
- Professional Supervision Required: You can’t trust an average welder to perform laser welding safely. You need skilled operators with both laser and welding expertise to do the job right. Unfortunately, experts with this technology might be scarce in some areas.
Applications of Laser Welding
As laser welding can elevate production capabilities and manufacturing processes, many industries found it essential to stay ahead in today’s cutthroat market.
Here are some current applications of laser welding.
Automotive Industries
Laser welding can assemble vehicle parts like panels, frames, doors, and powertrain components seamlessly. Since laser welding works well with thin metal components, it’s highly reliable in constructing modern vehicles that are lighter and more fuel-efficient.
Medical Industries
Cleanliness is integral in producing surgical equipment, medical implants, and diagnostic tools to ensure they’re free of contaminants. Laser welding ensures the meticulous production of medical equipment because of its ultra-precise welds with minimal thermal damage.
Electronic Industries
The demand for thinner and more sophisticated electronic components has steadily increased in recent years. As a result, manufacturers commonly use laser welding to produce robust and high-quality electronic components like circuit boards, resistors, capacitors, and inductors
Enhance Manufacturing Processes and Boost Production Capabilities With Laser Welding
With its unparalleled efficiency, accuracy, and reliability, laser welding is an ideal choice for manufacturers seeking to expand production capabilities, reduce turnaround time, and streamline high-volume production lines. Businesses from the automotive, medical, and electronic component sectors have already adopted this innovation in their manufacturing processes to meet dynamic market demands.
For expert laser welding solutions, visit Denaliweld and find state-of-the-art laser welding machines and services for your business.
