joining process

TIG welding stands for Tungsten Inert Gas Welding. It is one the metal inert gas welding used frequently in the manufacturing industry. It is also known as Gas Tungsten Arc welding(GTAW). It is used in those cases where high purity is needed to be maintained in the welded joints. For example, you cannot imagine nuclear power-plants, aviation companies, food and beverage companies and pharmaceuticals without the application of TIG welding. Most of the times it is used for welding non-ferrous metals. Like any other inert gas welding, it uses an inert gas for shielding. Most of the times, Argon or Helium is used for the inert gas shielding.

Please Read Different Types of Casting Process and their advantages. 

For more info about TIG, you can go through TIG advantages and Disadvantages 

TIG welding Working Principles

There are some basic differences between Metal Inert Gas (MIG) welding and the TIG. In the MIG the metal is continuously fed as a filler metal while doing the welding. But in TIG the base metal is melted and the filler metal is hand fed at the same time. The Tungsten stick is not consumed and works as an electrode.  So the basic difference between TIG and MIG is the non-consumable electrode used in TIG. While the welding process is going on the total welding area is shielded by the inert gas helium or argon. The inert gas is used to avoid the contamination of the welds from the environment.

TIG is not an easy task. It is the most complex form of welding. Let’s discuss the techniques-

Techniques for Performing TIG welding

• The angle of the welding torch should be 15-20 degrees apart from the direction of the welding. This is to be ensured otherwise the visibility of the welding path will be a problem. The quality of the welding will not be up to the mark without this technique.
• The filler metal should be kept at a distance from the tungsten electrode. Otherwise, there is a possibility of the contaminating the electrode. So filler should be kept at a very low angle.
• The torch will be melting the base metal and the melted base metal will be performing the fusion of the filler metal. The tendency to melt the filler metal with the torch should be avoided.
• The preparation of the tungsten electrode should be carefully done with the grinding wheel. It will be like sharpening the pencil. But for welding of the softer metal like Aluminium the tip should be flattened. The tungsten electrode tip just has to be touched against the grinding wheel.
• You have to be very careful when welding the stainless steel. Too much heat can deteriorate the welding quality. The welding flame colour should be in the range flaxen to salmon. Too much oxidized dark greyish and dirty flame is undesirable. This colour resembles too much flame. With increasing travel speed and lesser current flow, the problem of overheating of the flame can be avoided. Reducing the diameter of the filler metal can also solve this problem.

TIG welding Advantages in manufacturing

• TIG is free from flux. So the TIG welded parts are totally free from corrosion. It is the very clean form of welding.
• Metals like Aluminium are very delicate and care should be taken at the time of welding. Normal welding is not suitable for Aluminium as it is can deform the metal as a result of thermal stress generation.
• TIG welding can be performed in any suitable positions- vertical, horizontal or overhead. Due to its general arrangement, it gives a better view to the welder to complete the job. You can complete the job within a very short time in comparing to the other welding processes.
• Pressure tight joints like Gas pipelines can be welded with ease. TIG provides great strength with very negligible distortion.
• It is a high-speed method and very clean with great precision. The quality of the welding is superb.
• The electrode is non-consumable. So the welding is flawless as there is no need to change the electrode.
• Thinner parts can be welded without any deformation. The finish is superior.
• The welding can be done without the inclusion of the filler metal.

TIG Disadvantages

• The filler deposition rate is very low in TIG welding method. As a result, it can be a slower process in comparison with electric arc welding.
• As the welding is complicated, highly skilled technicians are needed to successfully complete the job.
• GTAW produces intense rays of light which can be very dangerous for the eyesight of the welder or the surrounding people.
• The initial cost of the machine and a man-power appointment can be high.
• You cannot join thicker sheet metal parts with TIG welding.
• TIG welding needs clean and tidy metal surface for a better weld quality. So surface preparation can be a time-consuming It can cost some money too.

TIG Application

• TIG or GTAW is used frequently in welding lightweight aircraft. MIG almost serves the purposed of the TIG. But in case of lightweight aircraft manufacturing, you have to use TIG welding. Complex but light elements of the aerospace industry can be welded with TIG.
• Stainless steel, Aluminium, high carbon steel, gold, bronze, nickel, copper and many unconventional metals can be welded in this process.
• Automobiles work with sheet metals. The sheet metals welding of the automobile is done with TIG. The automotive vehicles have to endure a lot of stress in their lifespan. So the precision, as well as strength, is needed to be ensured. The welded joints are not rusted and also corrosion free.
• Repairing tools without the trace of repair joints can be made by the TIG. Toys, Aluminium tools, metal parts, car parts all can be repaired through the TIG welding method.
• The use of TIG is not limited to industrial works. It is also used in arts.

Using TIG or GTAW in your manufacturing plant depends upon the type of prototype or final product you are building. Advantages and disadvantages are there. A manufacturing plant needs to go through these points and act accordingly. TIG is high-quality welding with affordable price but at the same time, it needs a skilled technician and some preparation of the metal surfaces.