Metal powder is a metal that has been broken down into a powder form. Metals that can be found in powder form include aluminium powder, nickel powder, iron powder and many more. There are four different ways metals can be broken down into this powder form:
- Direct Reduction
- Gas Atomization
- Liquid Atomization
- Centrifugal Atomization
Processes
The following processes can be used to produce metal powder:
- Direct reduction is the result of blending carbon with iron oxide ore, heating the mixture, removing the sponge iron from the carbon, grinding it, annealing it, and regrinding to make the powder form usable for manufacturing.
- Gas atomization occurs when a molten metal is passed through a passageway to a gas-filled chamber that cools the metal. As it falls, it is collected and annealed into a powder.
- Liquid atomization is similar to gas atomization, but instead the metal is sprayed with high-pressure liquid which solidifies the droplets more rapidly. This results in the powder being more porous, smaller, and cleaner.
- Centrifugal atomization occurs when a metal is put into a chamber as a rod and electrically melted, at the end of the rod, to produce melted droplets that fall into another chamber and then solidify.
Types and Uses
- Aluminum powder: Fireworks, metallic paints, manufacturing in solar cells in the green energy sector
- Bismuth powder: Production of batteries, welding rods, creating alloys
- Cadmium powder: Glazed used on ceramics, transparent conductors, nickel-cadmium batteries
- Iron powder: Magnetic products, printing, brake pads, certain types of dyes and stains
- Nickel powder: used for corrosion resistance, such as in the marine industry
- Raney nickel: used as a catalyst
- Platinum black: used as a catalyst
- Titanium powder