Consequently, why is flash important in forging?
Excess metal is squeezed out of the die cavities; this is called flash. The flash cools more rapidly than the rest of the material; this cool metal is stronger than the metal in the die so it helps prevent more flash from forming. This also forces the metal to completely fill the die cavity.
Similarly, why flash does not form in true die forging? The process is therefore called "flashless forging", and is sometimes called "enclosed die forging". The process is used to produce a near-net or net shape forging. The dies make no provision for flash because the process does not depend on the formation of flash to achieve complete filling.
Regarding this, what is flash and why is it desirable in impression die forging?
The flash, in a sense, becomes part of the tool and helps to build up pressure inside of the cavity. The increased pressure promotes flow of metal into features of the impression previously unfilled.
What is the major advantage of flash less forging?
This process carried out in an elevated temperature which in between cold and hot forging. Better control of grain flow is achieved in flashless forging as it eliminates the grain flow that lies at 90° to the free surface as in close die forging.