Which one of the following is a solid state joining process?

Explanation:

Welding

The joining of two similar or dissimilar metals with each other. It comes under permanent fastening.

There are basically three main types:

1. Solid-state welding
2. Liquid state welding
3. Solid/Liquid state welding

1) Solid state welding: 

• It is a group of welding processes that produces coalescence at temperatures essentially below the melting point of the base materials being joined, without the addition of filler metal. They are a homogeneous group of welding.
• No heat resources will be required but the pressure may be applied externally for welding.
• It is classified into five groups:

1. Explosive welding
2. Friction welding
3. Ultrasonic welding
4. Diffusion welding
5. Forge welding

2) Solid/Liquid state welding:

• These methods are used when the metals to be joined cannot withstand the high temperature produced in arc and gas welding.
• It is heterogeneous group of welding.
• It is classified into :

1. Brazing 
2. Soldering

3) Liquid state welding: 

• It is a group of welding processes that produces coalescence at temperatures essentially below the melting point of the base materials being joined, with the addition of filler metal.
• They are a homogeneous group of welding.
• Heat resources will be required for welding.
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