Application of TIG & MIG Welding in Manufacturing

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Applications of TIG and MIG welding in Manufacturing

What is welding?

A fabrication process that joins materials, usually metals, permanently through localized coalescence to become one.

Coalescence of materials is achieved by :

heating them to suitable temperatures with or without the application of pressure

by the application of pressure alone, and

with or without the use of filler material.

TIG welding(Gas Tungsten Arc Welding)

Gas tungsten arc welding is an arc welding process that uses a non-consumable tungsten electrode and an inert gas for arc shielding.It is also known as GTAW.

Equipments use in TIG: Gas supply (cylinder) Electrical power source

(AC/DC) Electrode holder, torch or

gun Connection cables Hose (for gas supply) Tungsten electrode Coolant Filler rods

Working principle:

An arc is established between the end of a tungsten electrode and the parent metal at the joint line..

A constant-current welding power supply is used to produces energy which is conducted across the arc through a column of highly ionized gas and metal vapors known as a plasma.

Argon and helium are the most commonly used shielding gases.

Characteristics of the TIG welding process:

Uses a non-consumable tungsten electrode during the welding process,

Uses a number of shielding gases including helium (He) and argon (Ar),

Is easily applied to thin materials, Produces very high-quality, superior welds, Welds can be made with or without filler metal, Provides precise control of welding variables (i.e. heat), Welding yields low distortion, Leaves no slag or splatter.

QUALITY: Gas tungsten arc welding affords

greater control over the weld area than other welding processes,

It can produce high-quality welds when performed by skilled operators.

Maximum weld quality is assured by maintaining cleanliness—all equipment and materials used must be free from oil, moisture, dirt and other impurities, as these cause weld porosity and consequently a decrease in weld strength and quality.

Applications: TIG is most commonly used to weld thin sections of stainless

steel and non-ferrous metals such as aluminum, magnesium, and copper alloys.

The aerospace industry is one of the primary users of gas tungsten arc welding,

It is also frequently employed to weld small-diameter, thin-wall tubing such as those used in the bicycle industry.

TIG is often used in piping of various sizes.

TIG in aerospace industry: Aerospace industry uses lite

metals (Aluminum and its alloy) thin sheet and need high quality welding. So TIG is more suitable for it.

Fig : Fuel pipes A320 AIRBUS

Bicycle industry:

In Bicycle industry, TIG is frequently employed to weld small-diameter and thin-wall tubing welding.

Fig : TIG in Bicycle industry

Others industry: Tig welding also used for others

industrial purposes. Such as for various piping , Joining thin material in automobile industry.

ADVANTAGES AND LIMITATIONS OF TIG WELDING:

ADVANTAGES:

No flux is used. Welding is smooth and sound

with fewer scatters. Very suitable for high quality

welding in thin materials. Very good process for welding

non-ferrous metals and stainless steels.

The surface finish is good. The equipments are portable

LIMITATIONS:

Tungsten inclusion is hard and brittle.

Equipment costs are high

In steel welding operations, TIG is slower and the most costly one

Filler rod end, if by chance comes out, then inert gas shield can cause weld metal contamination

MIG:

Metal inert gas (MIG) welding also known as MAG and GMAW.

It is a semi-automatic or automatic arc welding process in which a continuous and consumable wire electrode and a shielding gas are fed through a welding gun.

an electric arc forms between the consumable wire electrode and the workpiece metal(s), which heats the workpiece metal(s), causing them to melt and join.

Equipment and Set up:

1. Cylinder2. Pressure regulator3. Pressure gauge4. Flexible hose5. Welding gun6. Power source7. Welding return lead and clamp8. Earth connection9. Shielding gas cylinder10. Flow meter11. Wire feed12. Welding cable assembly13. Cooling system

MIG Welding Process: MIG welding is a gas shielded metal arc

welding process using the heat of an electric arc between a continuously fed, consumable electrode wire and the material to be welded.

A wire of copper coated mild steel is fed continuously from a reel through a gun with a melting rate up to 5m/min.

Current through the wire ranges from 100 to 400 A depending upon the diameter of the wire.

CO2 is principally used apart from argon or argon-helium mixture as shielding gas.

The welding machine is a dc constant voltage machine.

Applications of MIG Welding in

manufacturing:Why MIG welding is used in Manufacturing? High productivity can lead to higher profits. In manufacturing, productivity is the central focus. The primary advantage of MIG welding is welding speed. It is much quicker than traditional welding. High productivity can be achieved in many manufacturing operations with the use of MIG welding for its clean welds. It welds metals quickly. It is highly economic.

Applications of MIG Welding in manufacturing: (cont’)

1. Automotive repair.

2. Rebuilding equipment.

3. Overlay of wear resistant coating.

4. welding pipes.

5. It can even be used to reinforce the surface of a worn out railroad track.

1. Automotive repair

repairs can be carried out on a number of different vehicles whether they be large, small, light, or heavy.

capable of proving a strong weld even down to 0.5mm. 

2. Rebuilding equipment:Rebuilding:-to repair, especially to dismantle and reassemble with new parts. Example: to rebuild an old car.When it comes to fixing broken parts in the field, there are three steps to master:* Cutting and removal of the failed component.* Preparation of the new joint/part.* Welding and cleanup. worn parts can be repaired by using MIG welding in a variety of coatings (stainless steel, bronze, nickel, aluminum or hard surfacing) and in a range of hardness, for a fraction of the cost of purchasing a new part.

3.Overlay of wear resistant coating:

1. Coatings for Soft Bearing Surfaces2. Coatings for Hard Bearing Surfaces3. Coatings for Resistance to

Abrasion4. Coatings for Resistance to Fretting

and Surface Fatigue5. Coatings for Resistance to Erosion6. Coatings for Low Friction and Non-

stick Properties

4. weld pipes:It is more economical to use a track based robotic welding system than it is to actually man the assembly line. Special welding equipment will be needed.

Four Reasons to Choose Automated Pipe Welding with Robots:

1. New Technologies2. Flexibility3. Weld Quality4. Productivity

5.To reinforce the surface of a worn out railroad track:it can even be used to reinforce the surface of a worn out railroad track.

It can be difficult to join metals of different types, but by choosing the right filler wire you can actually achieve it over time.

Comparison: TIG & MIG

MIG Semi automatic or automatic

process. A consumable bare wire

electrode fed continuously into the weld pool through torch by spool.

An inert gas, e.g. argon, has a fluxing action and creates a protective shield around the weld pool.

The feed and flow rate are set by the operator.

Does not produce slag. Used on sheet metals.

TIG Utilizes a non-consumable

tungsten electrode An electric arc is formed

between a non-consumable electrode and the metal being welded.

An inert gas such as argon creates a protective gas shield.

A filler metal is added manually.

No slag is produced.

Safety:1. Fumes and Gases :

1. Keep your head out of the fumes2. Use enough ventilation, exhaust at the arc, or both, to keep fumes and gases from your breathing zone and the general area.

2. Electric Shock : 1. Do not touch the electrode or metal parts of the electrode holder with skin or wet clothing2. Keep dry insulation between your body and the metal being welded or ground3. The coil of wire is ‘electrically hot’ so do not touch it.

REMEMBER: Gas Cylinders require SPECIAL safety precautions

1. Cylinders must be secured in an upright position

2. Cylinders should be located in an area away from arc welding, cutting, heat, sparks, and flame

Conclusion: TIG welding needs highly skilled workers to produce high quality

weld. Maximum weld quality is assured by maintaining cleanliness—all

equipment and materials used must be free from oil, moisture, dirt and other impurities, as these cause weld porosity and consequently a decrease in weld strength and quality.

MIG welding is a huge improvement over some of the previous techniques.

MIG welding will help contribute to the creation of automobiles, the building of bridges, and even more importantly, a more efficient way to weld.