Advantages and Disadvantages of Friction welding: 

Advantages: 

It is environment friendly process without generation smoke etc. 

Narrow heat affected zone so no change in properties of heat sensitive material. 

No filler metal required. 

Welding strength is strong in most cases. 

Easily automated. 

High welding speed. 

High efficiency of weld. 

Wide variety of metal can be weld by this process. 

Disadvantages: 

This is mostly used only for round bars of same cross section. 

Non-forgeable material cannot be weld. 

Preparation of work piece is more critical 

High setup cost. 

Joint design is limited.