Solid phase welding
There are several advantages if welding can be carried out without the melting and solidification of metals. Solid-phase welding processes namely friction welding (FW), explosive welding (EXW), Induction pressure welding (IPW), ultrasonic welding (USW) and several cold pressure welding (CPW) processes satisfy this requirement and hence facilitate welding of many dissimilar metal combinations. These are required for electrical, transition pieces and many other critical products manufacture.
Diffusion bonding where coalescence is produced using pressure, temperature and time with or without using filler in a controlled atmosphere finds a variety of applications in many critical component manufacturers required for nuclear, aerospace and defense sectors.
Friction welding process has many variants.1.Inertia drive2.Continuous drive3.Orbital4.Positional arrest.5Radial6.Friction stir7.Friction surfacing8.Friction stud etc.Each of the process is employed for specific applications in various industrial sectors.
Explosive welding
1. Parallel configuration: Target plate is hit by flyer plate with high impact energy causing mechanical and metallurgical bond.Explosive selection,packing density,stand off distance are required conditions to get weld strength. Dissimilar metal combinations :Al-cu,Al-steel,Al-stainless steel,Al-titanium,Cu-stainless steel,Ti-stainless steel,Brass -steel are some of the plate to plate cladding applications.Dissimilar metal tube to sheet welds find use for heat exchangers.
2.Angular configuration: In this system flyer plate is oriented at the recommended angle to the target plate.
Safety for handling and storage of explosives is very important and operation to be carried out in specific areas not populated .