Flash welding is an electrical resistance based butt welding process and has the following advantages:
- A weld can be made over the whole joint area in a range of section sizes and complex shapes (for example from bicycle wheel rims to railway rails), although the sections to be joined should normally be closely matching. Mitre joints can also be formed, such as in welded metal window frames.
- A wide range of materials can be welded including steels, stainless steel, aluminium alloys, nickel alloys and titanium.
- A solid phase, forge weld is made, and any molten metal and contaminants formed at the interface during heating are squeezed out into the upset. Thus, solidification cracking and porosity are not normally an issue.
- The process is normally automatic or semi-automatic and process monitoring can provide an indication of weld quality.