The world of precision mechanics involves numerous manual processes and operations. Among these, one of the most versatile and flexible is MIG/MAG welding.
MIG and MAG refer to two types of welding involving the use of a shielding gas, and it is the latter that distinguishes the two processes. Both are widely used because they reduce processing costs and are suitable for very high production rates.
Let us look in detail at what the MIG/MAG welding process is and how it works, what the acronyms MIG and MAG mean, and the difference between the two processes.
What is MIG/MAG Welding and How it Works
The MIG/MAG welding process developed immediately after the Second World War, and grew exponentially in popularity because it was very cheap and fast. On a technical level, it is referred to as continuous fused electrode wire welding protected by a covering gas.
The process starts with a generator: the current delivered produces an electric arc between the fused electrode wire and the material that will later be welded.
As machining begins, a shielding gas flows from the torch into the weld pool to stabilise the arc produced by the current and to protect the material from contact with atmospheric gases. As the metal of the MIG/MAG welding wire melts, it joins the weld pool.
What does MIG/MAG Welding mean?
The acronyms MIG and MAG refer to the shielding gas used during the welding process:
- MIG stands for Metal Inert Gas: in this welding process, an inert gas is used, meaning one that does not react with the weld pool. Examples of inert gases are argon and helium;
- MAG stands for Metal Active Gas: the gas involved in MAG welding is active, meaning it participates chemically in the fusion process. The most commonly used active gases include argon with a percentage of carbon dioxide and oxygen.
What are the Differences between MIG and MAG Welding?
So, is it better to choose an inert or an active gas? The choice between MIG or MAG welding will not affect the quality of the end result, it is instead a decision based simply on the properties of the metal involved.
The argon in MIG welding, as mentioned, does not mix with other elements in the welding process, carrying the current more easily and preventing contact of the weld pool with atmospheric gases. This makes it possible to deoxidise certain materials, such as aluminium, for which MIG welding is widely used.
As far as MAG processes are concerned, carbon dioxide has greater penetration power and increases arc stability on materials such as steel or stainless steel.
Pros and Cons of MIG/MAG Welding
As mentioned above, MIG/MAG continuous wire welding is an extremely productive process and can handle very high rates: the wire does not terminate, so there is no need to replace the electrode. MIG and MAG welding lends itself to the treatment of a wide range of metals, thanks to the possibility of adjusting the shielding gas and generator parameters. Moreover, MIG/MAG welding machines can be found on the market at lower prices than machines required for other types of welding.
Despite the apparent simplicity of the process, good training is essential to complete a job well done. If you choose to weld with the MIG/MAG process, it is necessary to equip closed, unventilated spaces so that shielding gas is not dispersed into the atmosphere.
Another defect in MIG/MAG welding can result from incorrectly setting the heat input. By not adjusting the shielding gas parameters, in fact, the weld could be ruined: too high a heat input will lead to excessive penetration, if too low, on the other hand, it may not produce any fusion at all.
Bonanomi Mechanical Machining
Bonanomi manufactures high quality precision mechanics that meet the individual requirements of the world's largest machine tool manufacturers. For over 70 years, the company has been passionately and expertly producing customised precision engineering products, consulting services and mechanical machining for third parties.
From the clamping plates, top products in the Bonanomi catalogue, to the dressing plates, from the squares to the control rulers: the Bonanomi express shop is a guarantee of quality, competence and professionalism.