Welding is a fabrication or sculptural process that joins materials, usually metals or thermoplastics, by using high heat to melt the parts together and allowing them to cool, causing fusion. Welding is distinct from lower temperature metal-joining techniques such as brazing and soldering, which do not melt the base metal. In addition to melting the base metal, a filler material is typically added to the joint to form a pool of molten material (the weld pool) that cools to form a joint that is typically stronger than the base material. Pressure may also be used in conjunction with heat, or by itself, to produce a weld.
In this type of welding, an electric arc is produced between an electrode and the surface of a workpiece. The electrode can be made from a variety of materials including carbon, steel, or stainless steel. One of the main benefits is that it’s incredibly versatile and can be performed in any position, including horizontal, flat and overhead. This versatility makes the welding suitable for a range of applications, from do-it-yourself (DIY) projects to professional construction projects.
This type of welding is also a popular choice because it’s easy to learn and enables welders to get started quickly. In addition, the welding equipment (power source – either AC or DC, electrode holder, work cable etc.), is relatively inexpensive, so it’s suitable for almost any budget. MMA welding uses two electrodes in the welding arc. One of the electrodes is coated in flux. This creates a protective sheath around the weld until it cools, which reduces the chance of impurities getting into the weld pool.
The core of these electrodes is made from various materials, including steel, copper, graphite, and iron. The type of coating you use depends on the metal you’re working with. For example, some coatings are better suited for steel than others. You can find MMA rods that are compatible with most types of metal, though, so it’s not too difficult to find one that will work.
The power source can be a transformer, inverter or rectifier. The difference is in the type of current used to generate the arc. For example, a transformer welder is often used for heavy industrial applications and uses an AC to create the arc. A rectifier welder creates an arc with DC. An inverter can adjust between AC and DC currents. In addition to being simple to set up and operate, the welding power sources are also very affordable, making this type of welding a good choice for DIYers with little or no experience in arc welding.
The Two Kinds of MMA Welding
Shielded Metal Arc Welding (SMAW) – also known as stick welding. This is the most basic and portable kind of welding, but also the slowest. It’s not known for producing particularly clean or precise welds, but it has its uses. Flux-Cored Arc Welding (FCAW) – it uses a special tubular wire filled with flux; it can be used with or without shielding gas.
Tungsten inert gas (TIG) welding is a gas metal arc welding process that uses a non-consumable tungsten electrode to produce the weld. The weld area is protected from atmospheric contamination by an inert shielding gas (argon or helium), and a filler metal is normally used, though some welds, known as autogenous welds, do not require it. A constant-current welding power supply produces energy which is conducted across the arc through a column of highly ionized gas and metal vapours known as a plasma.
TIG welding is most commonly used to weld thin sections of alloy steel, stainless steel and nonferrous metals such as aluminium, magnesium and copper alloys. The process grants the operator greater control over the weld than other welding processes, allowing for strong, high-quality welds. TIG welding is comparatively more complex and difficult to master than other welding techniques. It is often used when quality welds are extremely important, such as in bicycle, aircraft and naval applications.
MIG and MAG Welding
Inert gas welding is a generic term that refers to two individual processes: metal inert gas (MIG) and metal active gas (MAG) welding. These processes are used to join metal by heating the workpieces and the filler material.
The most common type of metal inert gas welding is MIG welding, which uses an inert shielding gas to prevent oxidation of the weld. The flux-cored arc welding process is also an example of MIG welding and uses a continuous electrode fed through the welder. Both types use electrical energy that is transferred from a consumable or non-consumable electrode to the workpiece.
MAG welding is similar to MIG welding but uses an active shielding gas, such as carbon dioxide or argon/carbon dioxide mixtures, which can react with oxygen from the atmosphere. Gas tungsten arc welding (GTAW or TIG) and plasma arc welding (PAW) are other types of inert gas welding where different methods are used for forming and protecting the arc.
- Lower cost: MIG/MAG uses lower amperages than other processes, which means lower energy costs
- Higher productivity: Higher speeds are possible with MIG/MAG due to consistent heat input
- Easy operation: High deposition rates and good penetration make it easy to produce good welds even with minimal skill levels