Powder metallurgy is a specialized process for producing metal parts from powdered metal. It involves the following steps:

1. Powder Production

Atomization: Metal is melted and atomized into fine particles using gas or water.

Mechanical Pulverization: Brittle metals are crushed into fine powders.

Electrolytic Deposition: Metal powders are deposited from a solution using electric current.

Chemical Reduction: Metal oxides are reduced to metal powders using reducing agents like hydrogen or carbon monoxide.


2. Blending and Mixing

The metal powder is blended with other powders (if making an alloy) and lubricants or additives. This ensures uniformity and improves the properties of the final product.


3. Compaction

The metal powder is compressed in a die to give it the desired shape. High pressure is applied to form a "green" part, which has enough strength to handle but is still porous and fragile.


4. Sintering

The green compact is heated in a controlled atmosphere furnace below the melting point of the metal. During sintering:

Particles bond together through diffusion.

The porosity reduces, and the part becomes denser and stronger.



5. Secondary Operations (Optional)

Forging: Sometimes the part is forged to improve mechanical properties.

Machining: Precision parts may require further machining after sintering.

Heat Treatment: Enhances hardness or other mechanical properties.

Impregnation/Infiltration: Infiltrating the pores with lubricants or other metals to improve strength or lubrication properties.


Advantages of Powder Metallurgy:

Produces complex shapes with minimal material waste.

Ideal for making components like gears, bearings, and filters.

Can work with difficult-to-cast metals like tungsten and titanium.