By Scott Peart
Marketing Manager
Micro TIG welders, or pulse arc welders, uses electrical energy to create a plasma discharge. The high-temperature plasma melts metal in a small spot and is a clean and very controllable process—perfect for intricate and minute welding applications on precious and non-precious metals and takes place in milliseconds. Filler metal can also be added to build up joints and create strong and reliable welds.
Micro TIG welding makes it possible to discharge energy with a high degree of precision, in terms of the amount of energy discharged, how the energy is discharged, where the energy is delivered, and in a tiny spot. The weld spot is created as the tungsten electrode is withdrawn from the weld surface. The melting process starts from the outside and penetrates inward. Like traditional TIG welding, micro TIG welding can be used to add material, like fill wire, which is useful in many applications where additional material is needed for added strength. Additionally, micro TIG welding can be used to melt and fuse two parts together without the need to use fill wire.
An additional advantage of micro TIG welding is the extremely low energy input used to create the weld. This means that even heat sensitive parts or pieces can be welded with an exceptionally low chance of thermal damage. Micro TIG welding also helps reduce any distortion that would typically happen during other welding processes.
A typical micro TIG welder allows adjustment of voltage in a bank of capacitors, which release stored energy to form the weld spot. Many welders allow the time of discharge to be controlled as well. Between these two simple parameters, an entire range of weld spot sizes and penetrations are possible.
Linear-based micro TIG welders allow the shaping of the voltage and weld current during the arc discharge. The term “linear” welder comes from this type of welder’s unique ability to shape the welding voltage, or current output, into well-defined segments of known values. A linear welder is an exceptionally precise and high-tech welding solution that stores energy in a bank (or series) of capacitors and then controls the output power by means of high frequency switching and filtering of its capacitor energy bank. The capability to shape the output waveform allows the welder to meet the unique requirements of all metal types and difficulties. For example, silver is highly mobile as a liquid. Designing a specific waveform that creates a low peak current, which is sustained over a longer period can create beautiful and penetrating welds without unwanted and undesirable pushing from plasma blowing pressure. Jewelers in particular will appreciated the smoothness of the weld.
Micro TIG welding is a good all-around joining technology with lots of versatility, capable of creating a large range of weld diameters and good penetration. Small weld spots of around 0.25 mm are possible and, depending on the power of the unit, spot sizes of up to 4-5 mm can also be accomplished. Micro TIG welding is unaffected by the reflective properties of a metal, meaning the technology is the simplest and best to implement on reflective metals like silver. It can also be used on materials such as the ones below:
Sunstone manufactures micro TIG welders that also incorporate a resistance tack welder in the same unit. The tack weld feature allows for temporary placement before permanent joining and is a handy addition for shops working with solder joining on a regular basis.
Micro TIG welding can be electronically monitored with feedback strategies for automation and high-volume manufacturing applications.
Due to its ability to produce a solid and robust weld, micro TIG welding is used in a variety of industries such as the ones listed below:
One of the best sources for a micro TIG welding solution is Sunstone Engineering, a US-based developer and manufacturer of micro welders of all types. Sunstone manufactures four different models of micro TIG or pulse arc welders, each model capable of delivering different power ranges, energy control, higher cycle rates, and optics.