Electron Beam vs Laser Beam Welding
Electron beam welding (EBW) and Laser beam welding (LBW) are two very popular methods of joining multiple metallic components. But which process is the most effective?
The answer to this question depends on the application. In most cases, it is very beneficial to utilize both processes at different stages, especially with more complex manufacturing processes and components. In this post, we will briefly discuss each process and list the pros and cons of each.
Electron Beam Welding
Using EBW consists of a highly focused, high speed stream of electrons that bombard the component to be welded. The kinetic energy, which turns into heat upon impact, causes the two pieces to fuse together as a welded component. These ultra-high energy electrons allow for deep penetration and high aspect ratios, along with the smallest heat affected zone possible.
Because of the nature of electrons, a vacuum setup is required in order to be able to accurately control the diameter and flow of beam welding. The vacuum chamber also removes any possible gaseous contamination during the weld, which is critical to most aerospace welded metals, including titanium, nickel-based super alloys, and other refractory metals.
Pros of Electron Beam Welding
- No gas contamination
- Deepest weld penetration
- Clean environment is guaranteed
- Small heat-affected zone, similar to LBW
- Allows the welding of refractory or dissimilar materials
- Widely accepted in the industry
- No additional processing required
Cons of Electron Beam Welding
- High initial setup cost due to vacuum enclosure
- Size is restricted by vacuum chamber
- Longer cycle times than LBW
- Often requires complex tooling
- X-rays generated during process
Laser Beam Welding
The process of LBW consists of a focused beam of photons that are directed to the surface of the part to be welded. The laser provides a concentrated heat source, which allows the metal to be rapidly brought to its liquid state temperature. This rapid heating allows for a shorter interaction time versus other traditional methods, resulting in a smaller heat-affected zone.
There are several methods of LBW, including continuous wave and pulsed output. A continuous wave is just that, a continuous laser passing over the part during the weld process. By contrast, a pulsed output of lasers leaves a small pause between laser blasts. The advantage of a pulsed output is that it allows for cooling time, which is helpful when welding a heat sensitive metal.
Pros of Laser Beam Welding:
- Lower cost to setup than EBW (no vacuum or enclosures required)
- Can weld virtually any size component (not limited by chambers)
- Short cycle times
- Simple tooling requirements
- Minimal heat-affected zone
- No x-rays generated by the process
- Able to easily automate
Cons of Laser Beam Welding:
- Gas contamination is possible
- Smaller weld penetration than EBW
- Cannot weld dissimilar or refractory materials
- Unclean environment is possible
- Often require post-weld machining or heat treating