Extrusion processes

Extrusion Processes:

Extrusion is the process of confining the metal in a close cavity and then allowing it to flow from only one opening , so that the metal will take the shape of the opening. The operation is identical to the sequeezing of toothpaste out of the toothpaste tube.

By the extrusion process, it is possible to make component which have a constant cross section over any length as can be formed by the rolling process. Some typical parts can be extruded are shown:

Compexity of parts that can be obtain by extrusion is more than that of rolling, because the die required being very simple and easier to make. Also extrusion is a single pass process,unlike rolling the amount of reduction that si possible in extrusion is large. Generally brittle materials can be very easily extruded. It is also possible to produce sharp corners and different angles. It is possible to gets shapes with internal cavaties in extrusion by the use of spider die. Large diameters, thin walled , tubler products with execellent concentricity and tolerance charasitic can be produced.

Types of extrusion:

1: Direct extrusion or forward extrusion

2: Indirect extrusion or backward extrusion