Powder Metallurgy?

Answer 1

Powder metallurgy is a forming and fabrication technique consisting of three major processing stages. First, the primary material is physically powdered - divided into many small individual particles. Next, the powder is injected into a mold or passed through a die to produce a weakly cohesive structure (via cold welding) very near the true dimensions of the object ultimately to be manufactured. Finally, the end part is formed by applying pressure, high temperature, long setting times (during which self-welding occurs), or any combination thereof.
Source:http://en.wikipedia.org/wiki/Powder_metallurgy


Powder metallurgy uses sintering process for making various parts out of metal powder. The metal powder is compacted by placing in a closed metal cavity (the die) under pressure. This compacted material is placed in an oven and sintered in a controlled atmosphere at high temperatures and the metal powders coalesce and form a solid. A second pressing operation, repressing, can be done prior to sintering to improve the compaction and the material properties.

Powder metallurgy is useful in making parts that have irregular curves, or recesses that are hard to machine. It is suitable for high volume production with very little wastage of material. Secondary machining is virtually eliminated.

Typical parts that can be made with this process include cams, ratchets, sprockets, pawls, sintered bronze and iron bearings (impregnated with oil) and carbide tool tips.

Source:http://www.efunda.com/processes/metal_processing/powder_metallurgy.cfm


Also see:
http://www.azom.com/details.asp?ArticleID=132
http://www.maney.co.uk/search?fwaction=show&fwid=203

Answer 2

Powder metallurgy uses sintering process for making various parts out of metal powder. The metal powder is compacted by placing in a closed metal cavity (the die) under pressure. This compacted material is placed in an oven and sintered in a controlled atmosphere at high temperatures and the metal powders coalesce and form a solid. A second pressing operation, repressing, can be done prior to sintering to improve the compaction and the material properties.