Extrusion Advantages And Disadvantages

1.4 DIE DESIGN CONSIDERATION

For die design of extrusion the below given factors are to be considered.
1. Desired shape of the product
2. Material
3. Billet size
4. Process capacity
5. Extrusion ratio
6. Number of die cavities
7. Shrink factor
8. Process tool
9. Extrusion temperature
10. Extrusion pressure
11. Die material
12. Heat treatment of die material

1.5 EQUIPMENT USED
The equipment on the basis of the type of force used to drive the ram is classified as follows:

1.5.1 HYDRAULIC PRESS
The force required to derive the ram (punch) is supplied by hydraulic means to deform the metal plastically in this type of equipment.

1.5.2 MECHANICAL PRESS

The force required to derive the ram (punch) is supplied by mechanical

Now it is becoming essential to pay greater attention to the extrusion of section rod from round stock, as this operation offers the promises of an economic production route. The process is also attractive because of ready availability of press machines and the necessity to purchase expensive section stock corresponding to a multiplicity of required sections is eliminated. There are many advantage of extrusion which are given below:
1. Uniform cross-sectional area over a long length.
2. Low cost of dies making it economical to make small quantities of a shape.
3. Good surface finish.
4. Hardness and strain are increased due to strain hardening

1.7. LIMITATIONS OF EXTRUSION

Every process has some limitation and extrusion has also some limitation as given below
1. Most materials require high temperature and pressure, which makes the equipment costly.
2. Die material should be able to withstand the load, high temperature and wear.
3. In case of steel, the equipment is much costlier due to the magnitude of the temperature to which the metal must be heated (2300

Since the forces and the deformations generally are quite complex. It is usually useful to use simplifying assumptions to obtain a traceable solution. As the strain involved in plastic deformation process is very large, it is usually possible to neglect elastic strain and consider only the plastic strain (rigid-plastic region). The strain hardening is also neglected. The principal use of study of metal working process is for determining the forces required to produce given deformation for geometry prescribed by the process and is the ability to make prediction of the stress, strain, and velocity at every point in the deformed region of the billet. Since the calculation useful for selecting or designing the equipment to do a particular job. In this area an existing theory is generally adequate for the task. In general, any theory consists of three sets of