Process of joining metallic pieces by introducing non-ferrous alloys in the liquid state between the metallic piece and allowing to solidify is known as brazing.

Brazing:
Brazing is a metal-joining process in which two or more metal items are joined together by melting and flowing a filler metal into the joint, the filler metal having a lower melting point than the adjoining metal. Unlike welding, brazing does not involve melting the workpieces and commonly used filler metals are alloys of copper, silver, and aluminum.

Steps involved in brazing:
1. Cleaning: The first step in the brazing process is cleaning the surfaces of the metals to be joined. This is done to remove any impurities or contaminants that could interfere with the brazing process.

2. Fluxing: After cleaning the surfaces, the next step is to apply a flux to the joint area. The flux is used to prevent oxidation of the metal surfaces during the brazing process.

3. Assembly: Once the surfaces are cleaned and fluxed, the pieces to be joined are assembled and held in place with clips or other fixtures.

4. Heating: The assembly is then heated using a torch, furnace, or other heat source. The filler metal is introduced into the joint area as it is heated.

5. Cooling: Once the filler metal has melted and flowed into the joint, the assembly is allowed to cool slowly. This allows the filler metal to solidify and bond the two pieces together.

Advantages of Brazing:
1. Brazing can be used to join dissimilar metals.

2. The brazing process is less expensive than welding.

3. Brazed joints are strong and leak-tight.

4. Brazing can be used to join metals with thin sections.

Disadvantages of Brazing:
1. Brazing requires a flux to prevent oxidation of the metal surfaces.

2. Brazed joints may not be as strong as welded joints.

3. Brazing is not suitable for high-temperature applications.

4. Brazed joints may be subject to corrosion if the flux is not completely removed after brazing.