ELECTRON BEAM WELDING OVERVIEW

We Dive into the process, benefits, applications, and more.

Electron Beam Welding (EBW) Process

The electron beam welding process is one of the most technologically advanced welding processes available. In general, the eb welding process uses electrons to heat up and weld metals together. An electron gun accelerates the electrons to a very high speed. 

Then, a focuser narrows the electron beam to form a very powerful beam of electrons. 

Next, the beam of electrons make impact with the work pieces. Consequently, the very high kinetic energy of the electrons is rapidly transferred into heat. Finally, the workpieces are welded together to form a solid part. 

The whole process is performed under a vacuum in a chamber. This ensures there are minimal impurities from the air, and keeps the electron beam from dispersing. The result is a very high quality weld with great repeatability. 

 

Electron Beam Welding Machine

Electron beam welding machines are typically very advanced and complicated equipment. This is especially true relative to all other welding processes. Generally, the eb welding machine consists of these major components:
  • Electron Gun
  • Power Supply/Controls
  • Workpiece Fixturing and Controls
  • Vacuum Chamber

Electron Gun

The electron gun is responsible for generating the stream of electrons. The electron gun produces electrons by metal wire that is heated. At this point, there is not enough power to weld materials. The electrons must be accelerated and focused into a narrow beam. A high voltage power supply accelerates the beam of electrons. The high voltage system drives up the electron beam welding price considerably, due to its cost, and technical problems associated with high voltage systems. Finally, a focusing lens narrows the beam of electrons to form a high power density beam. Now, the beam can be applied for welding. As you can see, there is a lot going on in the electron gun.

Power Supply

As mentioned above, the power supply is one of the more expensive components of electron beam welding equipment. The power supply must be high voltage to accelerate the electrons fast enough to weld. The typical voltage range for electron beam welding equipment is 30kV to 150kV. The voltage can be either higher or lower depending on the conditions and desired weld depth. Weld depths can range from as small as 0.01mm to 250mm+. This is what makes the electron beam welding process so very capable.

Vacuum Chamber

The vacuum chamber is responsible for essentially housing the entire electron beam welding process. The purpose of the vacuum is to ensure there are no gas or contaminants in the atmosphere. Otherwise, the electron beam can scatter and produce inconsistent welds. 
 
The vacuum chamber can be as big or small as needed. It all depends on the size of the parts to be welded. As you can imagine, very big parts such as airplane wings would require very large chambers. Consequently, the cost of the electron beam welding equipment will be very high. Conversely, welding micro electronics requires a very small chamber which results in a lot lower price.
 

Workpiece Fixturing

The EBW welding process can never use people to move the work pieces. First, it is a vacuum process. They wouldn’t be able to breathe. Second, it is a very high voltage process and the risk for electrocution is very high. Third, the stream of electrons is very high energy, and as such emits strong X-rays. Obviously, this is no place for people to operate. Not even interns..

Consequently, this is a very automated process. Fixturing of the workpieces is setup on CNC tables. Once the tables are loaded with the workpieces, they are moved into the chamber computer controlled software. Likewise, the energy beam welding is also done through software. 

Advantages of Electron Beam Welding

Electron beam welding has many unique benefits when compared to other welding methods. The eb welding process is very precise. There is such a high degree of control over the weld versus traditional welding processes.

Also, electron beam welding is very repeatable due to the controls and automation involved. Consequently, the quality and mechanical properties of an electron beam welded part are excellent.

One of the more attractive benefits is the ability to weld dissimilar metals together. For example, eb welding is used to weld aluminum to titanium alloys.

The electron beam welding process produces a small thermo-heat affected zone. This is advantages for welding thinner materials where warpage and deflection can be a concern.

Electron beam welding is done entirely in a vacuum chamber. This virtually eliminates all impurities and contamination during the process. Furthermore, any impurities occurring in the materials will vaporize.

Disadvantages

The main drawback from eb welding is the possibility of cracking in the welds. This is due to excessive shrinkage from cooling down too fast.

Also, the cost of electron beam welding machines is substantially higher than other welding methods. Plus, the maintenance to keep the machine properly operating is higher too.

Applications of EB Welding

Since the first successful implementation of an eb welding machine in the 1950’s, EBW has shown up in many high end engineering applications were welding is needed. This follows the same trajectory of any new technological innovation. The EBW welding process is considered one of the most accurate and advanced welding techniques, even above friction stir welding.
The industries most commonly implementing electron beam welding includes:
  • Semiconductor
  • Aerospace
  • Medical
  • Energy/Nuclear
  • Automotive
  • Oil/Gas

Aerospace and automotive use it for electron beam welding aluminum. Being capable of welding very thin features makes electron beam welding aluminum an attractive solution for those industries.

Electronic components use low energy beam welding. They mostly weld micro components and low energy beam welding excels in this regard. 

Conversely, oil and gas industries use high energy eb welding to join very thick metal joints together. Electron beam welding excels in this application with its high speed and repeatability.

Electron Beam Welding Services

We are experts and leaders in eb welding. If you are looking for electron beam welding services we can help you. Whether you have no experience, or looking to expand your current eb welding manufacturing line, we can assist you. We help clients seamlessly with no knowledge at all of electron beam welding with initial design, to installing the finished machine. We want to make this easy for you by solving your electron beam welding process with our expert welding engineers. We can also have 3rd party manufacturers run your parts for you as well. Contact us by clicking the button below and get in touch with us so we can make your solutions to your problems a reality.
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