Page 85 - Module DMV20173

4.0 BULK DEFORMATION PROCESSES

Figure 4.21 Examples of Cold Extrusion. The arrows indicate the direction of metal flow
during extrusion.

4.4.7 THE ADVANTAGES OF COLD EXTRUSION

1. No oxidation takes place, and provided that lubrication is effective.
2. Good mechanical properties due to cold working, as long as the temperatures

created are below the re-crystallization temperature.
3. Good surface finish with the use of proper lubricants.

4. Good control of dimensional tolerances, reducing the need for subsequent machining
or finishing operations.
5. Production rates and costs that is competitive with those of other methods of

producing the same part.
6. Some machines are capable of producing more than 2000 parts per hours.

4.4.8 PRINCIPAL VARIABLES, WHICH INFLUENCE THE FORCES REQUIRED
TO CAUSE EXTRUSION

1. The type of extrusion.
2. The extrusion ratio.
3. The working temperature.

4. The speed of deformation.
5. The frictional condition.

BPLK 117 DMV 20173