projection welding process is a one type of resistance welding. In this process produces coalescence of welding metals, the heat generated from electric resistance to current through the work piece hold together with pressure applied to electrodes.
In this projection welding is more or less similar of spot welding process. The two welding work piece are hold with in pressure applied in electrodes. The projection are embossed (top part) in the work piece. Now the electrical current is passed through electrodes, when the projecting works metal to be melted and fuse which is contacted. Which projection coalescence will occur and joint the metal reaction of projection. The welded metal to be done. That should be having multiple work piece can be welded with single operation. The strength of welding joint depends on the nature of projection.
The thin flat sheet metal (24-13 gauge) can be welded by using button type projection. The cone type of projection used for 12 to 5 gauge metal sheets. In case, high thickness of work metal welded by using spherical type projection.
Advantages of projection welding process:
- Life of electrode is increased because of large contact surface.
- The large number of welded at single time
- Rust, oil, coating…etc. are not affected in welding.
- It having better heat control for different material composition and thickness.
- Life of electrode is longer than compared to spot welding electrode.