In this article, we will see the Definition, Main parts or Equipment, Working Principle, Advantages, Disadvantages, and Applications of Tungsten Inert Gas Welding (TIG Welding). We have also provided a PDF for the same.
It is a type of arc welding that uses tungsten as an electrode and the electrode is non-consumable. This welding is also known as Gas tungsten arc welding (GTAW).
What is Tungsten Inert Gas Welding?
Tungsten inert gas welding (TIG) is one type of arc welding method where we use a non-consumable tungsten electrode, to weld the two metallic bodies. The weld spot is protected from contamination by helium, argon, and other inert shielding gases. With this process, there is no longer a need for the filler metal that is typically used in the process of arc welding. This process makes this kind of weld highly resistant to the effects of corrosion.
Construction of Tungsten Inert Gas Welding Machine
A Tungsten Inert Gas Welding Machine consists of the following equipment
- Power Supply
- Inert Gas Supply
- Welding Torch/Holder
- Tungsten Electrode
- Shielding Gas
- Filler Rod
In TIG welding we need a constant power supply because if there is a fluctuation of current then it is hard for the welder to weld the joints properly.
The power supply can be of two types
- DC Power Supply
- AC Power Supply
In the DC power supply, we can weld steels, nickel, titanium, etc. And in AC power supply, we can weld magnesium, aluminum, etc. materials.
Inert Gas Supply
In Tungsten Inert Gas Welding, we need an inert gas supply to provide the shielding to the weld area from the atmospheric gas (For example, Oxygen, Nitrogen, and Hydrogen).In general, Argon is used as an Inert gas supply in TIG Welding. We will discuss this later in the Shielding gas section.
In TIG Welding the welding torch is designed to do either automatic or manual operations. However, in terms of construction, both are the same, in the manual torch, they are provided with a handle to hold it, and in the case of the automatic, they are designed to mount on an automatic machine.
Torches are provided with a cooling system either by water or air. When the Ampere of the current is less than 200 A generally we use air-cooling, but if it exceeds 200 A then we use water cooling to decrease the temperature of the welding torch. The inside portion of the welding torch is generally made of copper to increase the conductivity of heat. And the torches are provided with a holding arrangement (Port) to hold the Tungsten electrode firmly.
In TIG Welding we use a non-consumable electrode made of Tungsten or Tungsten Alloy. Due to the High-temperature resisting capacity (the Melting Temp of Tungsten is 3,422 °C ) of tungsten rather than any other metal, that’s why we use the tungsten electrode. The diameter of the electrode generally varies from 0.5 mm to 0.65 mm, and the length varies between 75 mm to 610 mm.
Shielding gases are used to protect the welding pool from atmospheric gases like nitrogen, and oxygen otherwise these gases can damage the welding surface by creating porosity, blowhole, etc. Choosing Shielding gases depends on the types of welding as well as the atmospheric condition the type of metal used for the operation and many more.
However, generally, we use Argon as a shielding gas in Tungsten Inert Gas Welding. Sometimes Argon-helium mixtures are also used in this type of welding.
As we already know, in TIG Welding, we use a non-consumable electrode that is Tungsten, so in some cases, we need separate materials to fill up the gap between two joints. The material of the filler rod can be anything, like carbon steel, aluminum, etc. It generally depends on the type of joints, the work-piece material, thickness, and also the properties of the workpiece.
Working Principle of Tungsten Inert Gas Welding
When we switch on the machine the high-frequency generator provides an electric spark. The electric spark is struck between the Workpiece and the Electrode either by touching the electrode with scrap material or by using a high-frequency unit. We need to do this operation (Touching with the scrap material) at least 2-3 times to warm up the electrode before the actual operation starts. Due to this, we can save the breaking of the electrode tip.
In actual operation, the heat generated by the electric spark fuses the metal from the joint area and produces a molten weld pool. The size of the pool depends on the size of the electrode and the amount of current supplied by the generator. The arc area is surrounded by an inert or reducing gas shield to protect the weld pool and the non-consumable electrode. The process may be operated autogenously, which means without filler material or filler material may be added by feeding a consumable wire or rod into the established weld pool. Tungsten Inert Gas Welding produces very high-quality welds across a wide range of materials with thicknesses up to about 8 or 10mm.
Video of TIG Welding Process
Applications of TIG Welding
This is specially used in the welding of refractory, sheet, and reactive materials. Tungsten Inert Gas welding can be used with such a large variety of metals, the process can be applied to several industries and aid in the creation and repair of many items. This form of welding is common in the aerospace, automotive, repair, and art fields.
- Aerospace: Aircraft and spacecraft are constructed in part by means of TIG welding.
- Automotive: Safe and secure construction is essential in the auto industry, as is making vehicles stand the test of time.
- Repair: TIG may be used in a number of repair applications. From fixing a child’s toy, like a wagon or old-fashioned pedal car, to repairing aluminum tools, this welding method comes in handy.
Advantages of TIG Welding
- TIG welding offers a solution for welding critical joints, and for situations where small or exceptionally precise welds are required.
- It can be performed with a wide variety of metals
- When done correctly, it produces a high-quality and high-purity weld compared with other joining processes, which is crucial in many applications.
- It can be done in both automatic and manual.
- Overall, it is one of the most efficient ways to join two metals.
- No slag is produced.
- TIG Welding can be done in any position.
Disadvantages of TIG Welding
- Tungsten welding can not be used for thicker sheets of metals.
- More complicated-Highly Skilled and professional workers are needed.
- The safety issue, welders are exposed to the high intensity of lights which can cause eye damage.
- The price of TIG welding services is high. However, costs will vary depending upon the materials being welded, and the scope of the project.
- It is a slow process welding.
What is TIG Welding
TIG (Tungsten Inert Gas) welding is a precise process that joins metals using a non-consumable tungsten electrode and inert gas shield. It’s commonly used for non-ferrous metals like stainless steel and aluminum. TIG welding provides control over heat and produces high-quality, clean welds with minimal spatter. It’s favored in industries requiring precision and aesthetic appeal, such as aerospace and automotive.
How to perform TIG Welding on aluminium
To perform TIG welding on aluminum, follow these steps. Begin by cleaning the aluminum surface thoroughly, removing any oxidation or contaminants using a stainless-steel brush. Next, set up the TIG welding machine with a non-consumable tungsten electrode and select the appropriate shielding gas, typically argon or a helium-argon mixture.
Adjust the machine settings for aluminum welding, including the appropriate amperage and balance control. Use a high-frequency start to initiate the arc and maintain a stable arc length. Employ a filler rod specifically designed for aluminum welding, matching the alloy being welded. Control the heat input by using a slow and steady travel speed. Post-weld, allow the aluminum to cool gradually to minimize distortion. Practice, experience, and understanding of aluminum’s unique characteristics are vital for achieving successful TIG welds on aluminum.
How to perform TIG Welding on Titanium
Performing TIG welding on titanium requires careful steps to ensure successful results. Begin by cleaning the titanium surface using a stainless-steel wire brush to remove any contaminants. Next, set up the TIG welding machine with a non-consumable tungsten electrode and shielding gas appropriate for titanium. Adjust the machine settings for the desired weld characteristics.
Preheat the titanium to a specific temperature range to reduce thermal stress during welding. Maintain a stable arc length and use slow, steady movements to control the heat input. Employ proper filler rod selection for titanium welding. Post-weld, allow the metal to cool slowly to prevent cracking. Practice, experience, and knowledge of titanium’s properties are essential for achieving high-quality TIG welds on titanium.
In conclusion, Tungsten Inert Gas Welding (TIG welding) is a versatile and precise welding process that has found widespread use in various industries, from aerospace to automotive manufacturing. Its ability to weld thin and delicate materials with minimal distortion makes it a popular choice for intricate welding applications. However, its slow welding speed and the need for skilled welders can limit its efficiency in high-volume production settings. Overall, TIG welding remains a valuable tool in the welding industry, offering a range of benefits for specific applications.