Welding of Copper and Copper Alloys

Classification and Welding Characteristics of Copper and Copper Alloys

1. Pure copper: Pure copper is often called purple copper. It has good electrical conductivity, thermal conductivity and corrosion resistance. Pure copper is represented by the letter + T} (copper), such as Tl, T2, T3, etc. Oxygen content is very low, pure copper less than 0.O1% is called oxygen-free copper, which is expressed by TU (copper-free), such as TU1, TU2, etc.
2. Brass: The copper alloy with zinc as the main alloy element is called brass. Brass is denoted by + H; (yellow) as H80, H70, H68, etc.
3. Bronze: The alloy of copper and tin used to be called bronze, but now the alloy of copper other than brass is called bronze. Tin bronze, aluminium bronze and sensitive bronze are commonly used. Bronze is represented by “Q,” (bronze).
The welding characteristics of copper and copper alloys are: refractory to fusion and easy to deform;
Easy to produce hot cracks;
Easy to produce blowhole.

Gas welding, inert gas shielded welding, submerged arc welding and brazing are the main methods for copper and copper alloy welding.
Copper and copper alloys have good thermal conductivity, so they should be preheated and welded with large linear energy before welding. Tungsten electrode hydrogen arc welding adopts direct current forward connection. In gas welding, neutral flame or weak carbonization flame is used for copper and weak oxidation flame is used for brass to prevent zinc evaporation.