Question

Which of the following is not a solid state metal joining technique?

• A. Friction welding
• B. Diffusion welding
• C. Electroslag welding
• D. Ultrasonic welding

Hint:

Solid state welding avoids melting; fusion welding involves molten phases. Electroslag welding is a fusion process.

Answer 1

The Correct Option is C

Solid state welding processes are those where coalescence is achieved without melting the base materials. Instead, pressure, time, and sometimes heat below the melting point are used to facilitate bonding. - Friction welding, diffusion welding, and ultrasonic welding are all solid state joining techniques. - Electroslag welding (ESW), however, is a fusion welding process. It involves melting of filler and base material by passing current through molten slag, which acts as the heat source. Hence, ESW is not a solid-state welding method.