Question

Which pair amount the following solid state welding processes uses heat from an external source

P. Diffusion welding
Q. Friction welding
R. Ultrasonic welding
S. Forge welding

• A. $Q$ and $S$
• B. $P$ and $R$
• C. $R$ and $S$
• D. $P$ and $S$

Answer 1

The correct option is D $P$ and $S$

$P$ and $S$