Page 81 - Module DMV20173

4.0 BULK DEFORMATION PROCESSES

b) INDIRECT EXTRUSION PROCESSES

1. Also called reverse, inverted or backward extrusion.
2. The dies move toward the un-extruded billet is shown in Figure 5.16 and Figure

5.17.
3. The frictional forces between the container walls and the billet are lower and the

power required for extrusion is less than for direct extrusion.
4. In practice, a hollow ram carries a die, while the other end of the container is
closed with a plate.

5. Frequently, for indirect extrusion, the ram containing the die is kept stationary,
and the container with the billet is made to move.

Figure 4.16 Illustrations of indirect extrusion process.

BPLK 113 DMV 20173