What is Heliarc Welding

Heliarc welding, also known as Tungsten Inert Gas (TIG) welding, is a welding process that uses a non-consumable tungsten electrode to create a weld. The process is named after the inert gas, helium, which is commonly used as the shielding gas in this welding technique.

Why Heliarc Welding Was Invented?

Heliarc welding, also known as tungsten inert gas (TIG) welding, In the early 1930s, Russell Meredith, an engineer at Northrop Aircraft Corporation, began experimenting with different ways to weld magnesium. He tried using a variety of shielding gases, but none of them were effective in preventing the magnesium from oxidizing. In 1941, Meredith discovered that argon was an effective shielding gas for welding magnesium. He patented his process and called it heliarc welding.

Traditional welding methods that used flame and filler metal, such as gas welding and brazing, were not suitable for welding magnesium due to its reactivity. So, Meredith came up with a new process that used a non-consumable tungsten electrode to produce an electric arc and an inert gas, such as argon or helium, to shield the welding area from atmospheric contamination.

This process allowed for precise control of the heat input and the amount of filler metal added, resulting in a strong, high-quality weld that was free from defects. In addition, the use of inert gas as a shielding medium prevented oxidation and other forms of contamination, making it ideal for welding reactive metals like magnesium.

How does Heliarc Welding work?

In Heliarc welding, a tungsten electrode is used to create an electric arc with the workpiece. The tungsten electrode is non-consumable, which means it does not melt or become part of the weld. Instead, it acts as a heat source and creates a plasma arc that melts the workpiece material.

A filler metal is often used in Heliarc welding to reinforce the weld and create a stronger bond between the two pieces being welded. This filler metal is manually fed into the weld area by the welder.

The welding area is protected from atmospheric contamination by a shielding gas, typically a mixture of helium and argon. This gas is used to protect the weld from oxidation and other atmospheric gases that could weaken the weld.

Advantages of Heliarc Welding

High-quality welds: Heliarc welding produces high-quality, precision welds with minimal distortion. The welds are clean, strong, and visually appealing, making them suitable for a range of applications.

Versatility: Heliarc welding can be used on a range of materials, including aluminum, steel, stainless steel, copper, brass, and other alloys. This versatility makes it a popular choice for welding in various industries.

Precise control: The non-consumable tungsten electrode and filler metal provide the welder with precise control over the welding process. This control allows for intricate welds and welding in tight spaces.

Disadvantages of Heliarc Welding

Complex process: Heliarc welding is a complex process that requires a skilled welder with experience in the technique. The process involves multiple steps and requires careful attention to detail to produce a high-quality weld.

Slow welding speed: Heliarc welding is a slow process compared to other welding techniques, such as MIG and stick welding. This slow speed can increase production time and costs, making it less suitable for large-scale projects.

Expensive equipment: Heliarc welding requires expensive equipment, including a power source, gas regulator, tungsten electrode, and filler metal. The cost of this equipment can make it a less attractive option for some welders and businesses.

Applications of Heliarc Welding

Heliarc welding is used in a variety of industries, including:

Aerospace: Heliarc welding is commonly used in the aerospace industry to weld aluminum and other alloys. The process produces high-quality welds that meet the stringent safety standards required in this industry.

Automotive: Heliarc welding is used to weld various parts of automobiles, including exhaust systems, frames, and fuel tanks. The process creates clean, strong welds that are visually appealing and durable.

Construction: Heliarc welding is used in the construction industry to weld steel structures, pipes, and other metal components. The high-quality welds produced by the process ensure the safety and durability of these structures.

In conclusion, Heliarc welding is a versatile welding technique that produces high-quality, precise welds on a range of materials. While it may be a complex and slow process, the benefits of the technique make it a popular choice in various industries.


What is the difference between TIG and Heliarc?

Heliarc welding is actually a type of TIG welding. "Heliarc" is an older term used to describe TIG welding that was commonly used by the Linde company when they first introduced this welding process. Today, TIG welding is the more widely used term to describe this process.

Heliarc welding is essentially the same process as TIG welding, but the term is no longer commonly used. The main difference is that Heliarc welding typically used helium as the shielding gas instead of argon. Helium has a higher heat conductivity than argon, which can make it a better choice for welding thicker metals. However, helium is also more expensive than argon, which can make it less practical for some applications.

In summary, Heliarc welding is an older term for TIG welding that used helium as the shielding gas. Today, TIG welding is the more commonly used term for this welding process, and argon is the most commonly used shielding gas.

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