Powder metallurgy is process of making useful component from metal powder it can be individual or mixed or alloy powder with or without inclusion of non metal.

Powder metallurgy is the art or science of manufacturing useful metallic or alloy article by compacting the metal powder or alloy powder in a die with little no melting followed by sintering.

It is a process of obtaining the desired shape of definite dimension from the loose powders.

The blended & mixed metal powders are then fed into suitable dies to give them desired shape. This process requires specific pressure. This is an important step in powder metallurgy, because proper shape of finished product governs many properties.

It is important because, It reduces void space between metal particles, It increases density of compact, It produces adhesion & cold welding of powders & It facilitates the sintering operation, By deforming the powder plastically & By increasing the contact areas between the powder particles.

The compacting is carried out in either hydraulically or mechanically operated press. The dies are usually made of high grade hardened steel with fine finish. The solid mass is called Green Compact.

Powder injection molding: The metal powder is converted into moldable state by mixing with binder. Binder also provide green strength & and great stability. Usually heating is done in order to force it through spruce & running channel. Process is similar to the injection moulding process of polymer.The process is also called as metal injection moulding. Powder injection metallurgy allows the production of metal or ceramic parts with the same flexibility and freedom in design.

There are 4 steps:

1. Feedstock preparation (compacting):In this stage powder is transferred into moldable state called feedstock. The feedstock consists of binder and powder.
2. Injection moulding: At this stage molten feedstock is injected into the die through a nozzle by injection pressure following the principle of screw action.
3. Debinding: After moulding binder component is removed. This is called as debinding.The type of debinding are thermal, catalytic and dissolving.
4. Sintering phase basically comprises of two stages. The first stage is thermal decomposition of the residual binder component.The second stage takes place in the porous part which contains only metal powder.

Uses: It is used for preparing parts with complicated shapes from materials like cemented carbide, tungsten, heavy alloy & ceramics