Page 79 - Module DMV20173

4.0 BULK DEFORMATION PROCESSES

Figure 4.13 The example of machine for extrusion.

a) DIRECT EXTRUSION PROCESS

1. Billet is placed in a chamber (container) and force through a die opening by a
hydraulically driven ram (pressing stem or punch) as shown in Figure 4.14.
2. The die opening may be round, or it may have various shapes, depending on the

extrusion shape desired.
3. The function of dummy block is to protect the tip of the pressing stem, particularly

in hot extrusion.
4. Figure 4.15 shows the direct extrusion for producing solid and hollow object.
5. Main problem about this type of process is that frictional forces are created

between the walls of the container and the metal (billet; this requires more force
and power to run the extrusion process).

BPLK 111 DMV 20173