SOLUTION

Fusion welding processes are the welding processes that we use without pressure. Even though the fusion welding processes are different from one another, in all the fusion welding processes, the base metal melts and flows into a weld joint. We normally use a filler metal for fusion welding. Then the filler metal also melts and flows into the weld joint. When the molten metal solidifies, it produces a solid fusion weld.

The three major types of fusion welding processes are as follows

1. Gas welding:
   1. Oxyacetylene welding OAW
2. Arc welding:
   1. Shielded metal arc welding (SMAW)
   2. Gas-tungsten arc welding (GTAW)
   3. Plasma arc welding (PAW)
   4. Gas-metal arc welding (GMAW)
   5. Flux-cored arc welding (FCAW)
   6. Submerged arc welding (SAW)
   7. Electroslag welding (ESW)
3. High-energy beam welding
   1. Electron beam welding (EB W)
   2. Laser beam welding (LBW)

Brazing

Brazing is a joining process. In brazing metal or alloy having a melting point below than the parent, metal is made to flow by capillary action into Space between the parts to be joined under the action of heat.

Brazing may be defined as the technique of joining two similar or dissimilar materials by the addition of special filler metal. If the alloy used has a melting point lower than 450°C, the technique is known as the soldering Brazing gives~ a much stronger joint than soldering. The filler metal used in brazing is known as a spelter. In brazing, metallic parts are joined by a nonferrous metal or alloy. The melting temperature of a spelter should be above 427°C and brazing is carried out above this temperature.