Tungsten Rods
The use of tungsten in spot welding of copper or brass materials is an application that can be preferred in certain special cases, but generally remains limited.
1. What is Spot Welding?
Spot welding (resistance welding) is a method of joining two metals by melting them under high current and pressure. It is generally suitable for steels, but special precautions are required for highly conductive metals like copper and brass.
Application Examples:
* Electrical terminal production: Tungsten-tipped electrodes are preferred for joining copper strips with spot welding.
* Brass connection parts: Tungsten-coated electrodes provide advantages in high-volume production when welding thin brass sheets.
* Motor coil end connections: Tungsten electrodes are used to minimize thermal spreading.
Additional Notes:
Electrode cleanliness is crucial; oxidized tips reduce weld quality. Using pulse mode or step current reduces spatter in thin copper/brass sheets. Post-weld cooling time should be properly managed to prevent surface deformation.
**2. Challenges of Spot Welding Copper and Brass**
Due to high thermal and electrical conductivity, heat spreads in the welding zone making melting difficult, higher current is required, and electrode wear occurs quickly.
3. Where Tungsten Comes Into Play
Tungsten is a very hard metal with a high melting point (about 3422 °C). It is used as an electrode or as a coating on electrode tips. It is especially preferred for welding soft and abrasive materials like copper or brass and for preventing rapid melting or deformation of electrode tips. Instead of using pure tungsten electrodes directly, tungsten-tipped or tungsten-coated electrodes are commonly used.
4. Alternatives and Recommendations
Chromium-zirconium copper electrodes are more commonly used for copper welding.
5. Conclusion
Tungsten is generally used as an electrode material rather than as a welding filler in copper and brass spot welding. Its durability provides efficiency in high-volume production, but if the equipment is not suitable, arc jumping or surface defects may occur.