Powder Production
Unique compared to other powder suppliers, LPW Technology offers powder manufactured by several different processes. Each process has distinctive advantages and disadvantages. The common processes are explained below. However, for specific enquires, including information on our range of pre-blended Tungsten Carbide containing Cobalt and Nickel matrix powders, please contact us directly.
Click here for further details on standard metal powders and conversion tables for powder sizing.
Gas Atomised
The most common method of powder production. Elemental feedstock is melted under an air or inert gas blanket, or under vacuum. The chamber is then backfilled with gas to force molten alloy through a nozzle where high velocity air, N, He or Ar gas impinges onto the flowing melt and breaks it up.
Powder is mostly spherical, with some asymmetric particles and satellites present. A satellite is when a smaller particle sticks to a larger one during solidification. Heat sizes range from 5kg to 3000kg. Size ranges from 0 to 500 micron. Yield within 20-150 micron range varies from 10 to 50% of total. Mostly used for Ni, Co and Fe alloys, also available for Ti and Al alloys.
Water Atomisation
Similar to gas atomisation but water is employed as the atomising medium. Mostly used for unreactive materials such as steels, produces irregularly shaped particles.
Plasma Atomisation
A relatively new technique that produces high quality and extremely spherical powder. Wire feedstock is fed into a plasma torch that with the aid of gases atomise the powder. Size ranges from 0 – 200 micron. Limited to alloys that can be formed into a wire feedstock.
EIGA (Electrode Induction melting Gas Atomisation)
Works with all alloys but is most economic with reactive alloys like Ti. Feedstock, in the form of bar, is rotated and melted by an induction coil. A film of molten metal flows downwards into a gas stream for atomisation. Therefore, material does not come in contact with either crucible or electrode during process. Powder size is 0 to 500 micron and morphology is similar to gas atomised. Process is cheap, clean, good for small batches, and produces small diameter powder.
Similar to EIGA process but the rotating feedstock bar is melted when it comes into contact with a plasma. Powders are extremely spherical but yields are limited below 100 micron, so price can be very high.
Centrifugal Atomisation
A simple process that is not in wide-spread use. A good compromise between Gas Atomised and Plasma Atomisation. Generates powder that is more spherical and has lower entrapped gas porosity than Gas Atomisation but not to the quality of Plasma Atomisation or PREP. However, is cheaper than both PREP and Plasma Atomisation. Best suited to larger batch sizes of less reactive low melting temperature alloys, but can also make Nickel superalloys.
