Fabrication of metal objects from a powder rather than casting from molten metal or forging at softening temperatures.
In some cases the powder method is more economical, as in making metal parts such as gears for small machines, in which casting would involve considerable scrap loss. In other cases, melting is impractical (e.g., because the melting point of the metal is too high). Powder metallurgy is also used to produce a porous product that will allow a liquid or gas to pass through it. See also metallurgy , sintering .