plasma arc welding feature image

Plasma Arc Welding is a liquid state welding process. Here in this paper we are going to study Components, Working Principle, Applications, Advantages, and Disadvantages of Plasma Arc Welding.

Note: PDF Available at the bottom of this article

Now, let’s start with the definition first.

Definition of Plasma Arc Welding:

Plasma arc welding is a liquid state welding process in which the metal to metal joint forms in a molten state. The hot ionized gases are known as Plasma. These hot ionized gases used to heat the work plates, and the joint is created due to fusion

Artificial plasma
Artificial Air Plasma

Construction Plasma Arc Welding:

The Plasma arc welding consists of the following components:

  • Filler Material
  • Power Supply
  • Plasma Console
  • Water re-circulator 
  • Plasma Welding Torch
  • Torch Accessory Kit (Tips, ceramics, collets, electrodes set-up gages)
components of plasma arc welding
1. Gas plasma, 2. Nozzle protection, 3. Shield Gas, 4. Electrode, 5. Nozzle constriction, 6. Electric arc

Filler Material:

In Plasma welding there is no filler material is used. If the filler material is used, then it is directly fed into the weld zone.

Power Supply:

The plasma arc welding process needed a high power DC supply to generate the electric spark in between the tungsten electrode and welding plates.

This welding can weld at a low 2 amp and the maximum current which it can handle is about 300 amp. It needs about 80 volts for proper working.

The power source consists of a transformer, rectifier and control console.

Plasma welding torch:

This is the most important part of the plasma welding process.

This torch is quite similar as used in TIG welding.

PAW torches are water-cooled because the arc is contained inside the torch which produces high heat, so a water jacket is provided outside the torch.

DC plasma torch
DC Plasma Torch

Water Re-circulator:

This mechanism is used to cool the welding torch by the continuous flow of water outside of the welding torch.

Torch Accessory Kit:

These kits are used to expanding the performance of the welding torch.

Working Principle of Plasma Arc Welding:

This is an arc welding process, a concentrated plasma arc is produced and directed towards the weld area.

The arc is stable and reaches temperatures as high as 33,000°C.

Plasma arc welding working diagram

A plasma is an ionized very hot gas composed of nearly the same numbers of electrons and ions.

The plasma starts between the tungsten electrode and the orifice by a low current pilot arc. What makes plasma-arc welding different from other processes is that the plasma arc welding is concentrated because it is forced through a relatively small orifice. Operating currents usually are less than 100 amp.

When filler metal is used it is fed into the arc as is done in Gas Tungsten-arc Welding. Arc and weld-zone shielding are supplied by means of an outer shielding ring and the use of inert gases like argon, helium or mixtures.

You may watch this video for a better understanding of Plasma Arc Welding:

Advantages of Plasma Arc Welding:

The following advantages of Plasma Welding are:

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  • Torch design allows better control of the arc.
  • This method provides more freedom to observe and control the weld.
  • The higher the heat concentration and plasma jet allow faster travel speeds.
  • The high temperature and high heat concentration of plasma allow the keyhole effect.
  • This provides complete penetration with the single-pass welding of many joints.
  • The heat-affected zone is smaller compared to GTAW(Gas tungsten arc welding).
  • It uses less current input as compared to another welding process.

Disadvantages of Plasma Arc Welding:

The following disadvantages of Plasma welding are:

  • It produces wider welds and heat-affected zones compare to LBW and EBW.
  • Plasma welding equipment is very costly. Hence it will have a higher startup cost.
  • It requires training and specialization to perform plasma welding.
  • It produces ultraviolet and infrared radiation.
  • The method produces higher noise on the order of about 100dB.
  • The torch is bulky and hence manual welding is a bit difficult and requires training as mentioned.

Applications of Plasma Arc Welding:

The application of Plasma Arc welding are:

  • This welding is used in marine and aerospace industries.
  • This is used to weld pipes and tubes of stainless steel or titanium.
  • It is mostly used in electronic industries.
  • Also, this is used to repair tools, die, and mold.
  • This is used for welding or coating on a turbine blade.

So this is all about Plasma Arc Welding, I hope you like my article. I also wrote articles on some other welding processes do check out those too.

And moreover do not forget to share the article on your favorite social platform.

More Resources for you

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Submerged Arc Welding
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Tungsten Inert gas welding

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What is Plasma Arc Welding?

It is a liquid state welding process in which, the metal to metal joint forms in a molten state. The hot ionized gases are known as Plasma. These hot ionized gases used to heat the work plates, and the joint is created due to fusion. 

Is Plasma Welding is Gas Welding?

No. It is Arc welding.

What are the components of it?

The following components are:
1. Filler Material
2. Power Supply
3. Plasma Console
4. Water re-circulator 
5. Plasma Welding Torch
6. Torch Accessory Kit (Tips, ceramics, collets, electrodes set-up gages)

Reference (External Links):

Media Credits:

  • Image 1: By Chocolateoak – Own work, CC BY-SA 3.0,
  • Image 2: Public Domain
  • Image 3: By Rudolfensis at English Wikipedia, CC BY-SA 3.0,
  • Image 4: Advances in Welding and Joining Technologies Dr. Swarup Bag Department of Mechanical Engineering Indian Institute of Technology, Guwahati, find at NPTEL
  • Feature Image: Public Domain, modified by author
  • Video: By Chip CM
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About the Author

Amrit Kumar

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Amrit is a Co-founder of Learn Mechanical Portal (Previously owned ""). He completed his diploma in Mechanical Engineering from Acharya Polytechnic Bangalore and also completed his B-Tech from Delhi.

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