Extrusion is the process of creating objects having very complex cross-sections. It is a relatively old process and was invented by Joseph Bramah in 1797. The beauty of this process is in its ability to work with brittle metals. The end product is also attributed with the exceptionally good finish.
The most common materials that are used in this process are polymers, metals, ceramic, concrete, clay and plastic. This process can work on these materials efficiently because the material is only subjected to compressive and shear stresses.
It can either be continuous i.e producing an item of infinite length, or it can be discontinuous i.e. producing several pieces of a particular item. It can be done with hot and cold materials alike.
In its simplest terms extrusion can be summarized as a set of steps and components:
- Production of Billet or Ingot: This is nothing but production of a standard sized metal.
- Billet is then either heated or left at room temperature, depending upon the nature of this process.
- The billet is then forced inside the die where it takes the desired shape.