In explosion welding (EXW), pressure is applied by detonating a layer of explosive
that has been placed over one of the components being joined, called the flyer
plate .The contact pressures developed are extremely high,
and the kinetic energy of the plate striking the mating component causes a wavy
interface.
This impact mechanically interlocks the two surfaces , so
that pressure welding by plastic deformation also takes place. The flyer plate is
placed at an angle, and any oxide films present at the interface are broken up and
propelled out of the interface. As a result, the bond strength from explosion welding
is very high.
The explosive may be a flexible plastic sheet or cord or in granulated or liquid
form, which is cast or pressed onto the flyer plate. The detonation speed is
usually in the range from 2400 to 3600 mfs; it depends on the type of explosive,
the thickness of the explosive layer, and the packing density of the layer. There is
a minimum denotation speed necessary for Welding to occur in this process.
Detonation is carried out with a standard commercial blasting cap.