Fundamental Basic Parameter Configurations
Use DC positive polarity for power polarity. Attach the workpiece to the positive terminal and the tungsten electrode to the negative terminal. This is ideal for welding thin thermocouple wires because it guarantees a consistent arc and incredibly little tungsten electrode loss.
Tungsten Electrode Diameter: To precisely manage the arc energy focused at the thermocouple wire tip, use a 1.0–2.0 mm cerium tungsten electrode with a tip honed to a tiny angle of 30°–45°.
Welding Current: Aligned with the diameter of the wire. To prevent the wire from burning out from too much current, set 5~15A for thin wires under 0.3mm and 15~30A for medium wires between 0.3 and 0.8mm.
Arc Voltage: Used with short arc operation to guarantee a full and spherical weld ball, it is regulated at 10–14V.
To completely cover the welding area and isolate the weld from air to prevent oxidation, set the argon gas flow rate to 6–10 litres per minute.
Configuring Auxiliary Function Parameters
Before welding, set the pre-air gas supply time to 0.5 to 1 seconds to remove any remaining air from the welding torch tubing.
To help the thermocouple wire tip ignite and melt into a ball fast, the arc starting current should be 10% to 20% higher than the standard welding current.
In order to prevent the weld ball from cooling quickly and cracking, the Arc Attenuation Time should be set at 1 to 3 seconds.
The delay time for argon gas is: Set at 3–8 seconds, continually providing argon gas to protect the high-temperature weld joint from oxidation and discolouration until the weld ball has fully cooled.
K-type and J-type base metal thermocouples, which are frequently used in hot runner systems, are compatible with this parameter scheme. The welded balls fully satisfy the specifications for long-term high-temperature operation in hot runner systems because they are strong and devoid of oxidation and porosity.
