Cold extrusion is generally done for material such as plastic, food materials and soft metals such as aluminium and brass. In cold extrusion, the materials are pressed by means of a ram. The lubricant used is graphite, zinc phosphate, calcium stearate, etc.
During the cold extrusion process, heat is produced in the material due to deformation.
Cold extrusion has many advantages over hot extrusion. The advantages are
- No oxidation occurs
- The strength of the extruded material is stronger
- The finish is better
- The tolerances are closer
- The energy consumption is lesser as not power is required for heating
Cold extrusion is used in the plastic and food industries. It is also used for producing components for the automative industry.