The diffusion welding process is one kind of solid state welding method. The weld joint is produced under a tremendous pressure applying on holding job at elevated temperature. The matched metal surface should be perfectly cleaned and mated also and finally grow together by atomic diffusion.
Diffusion welding method:
In diffusion welding process any surface can be welded except dead smooth surface. Every metal surface have a pick or heel point and valley point. In there have either metal oxide or dirt, grease etc. Initial both metals are mate together which metal face to be weld. Now hold it under huge pressure such like that the roughness of metals are deformed . This time the dirt or other impure materials are dispersed from weld surface.
The pressure which is applied for joining the surface is about 400 to 700 kg/cm2.
The weld metal surfaces are defused under huge amount of pressure. After a certain period of holding the entire area of contact surface is bonded.
This whole process is take a long period. If reducing the bonding or welding time then some heat may be applied on weld area.
Diffusion welded materials:
Zirconium alloys, Titanium alloys for aerospace components, nickel base alloys etc.
Dissimilar material can be welded with this diffusion welding application like Cu to Ti, Cu to Al, and Cu to Cb-
Advantages of diffusion welding process:
Due to cold welding process the base metal’s chemical or mechanical composition is not changed.
Continuous weld joint is made.
Clean joint is produced due to no use of flux or filler metal.
This welding method is suitable for joining of dissimilar metals.
Applications of diffusion welding:
Fabrication of composite materials.
This welding process has large use in atomic reactor plants.