Sintering is a method for making objects from powder, by heating the material (below its melting point - solid stage sintering) until its particles adhere to each other. Sintering is traditionally used for manufacturing ceramic objects, and has also found uses in such fields as powder metallurgy. A special form of sintering, not limited the solid state but still considered part of powder metallurgy is liquid state sintering in which at least one but not all elements are existing in a liquid state. Liquid state sintering is required for making cemented carbides or tungsten carbide.
The word "sinter" comes from the Middle High German Sinter, a cognate of English "cinder".
Sintered bronze in particular is frequently used as a material for bearings, since its porosity allows lubricants to flow through it or remain captured within it. In the case of materials with high melting points such as Teflon and tungsten, sintering is used when there is no alternative manufacturing technique. In these cases very low porosity is desirable and can often be achieved.
Sintered bronze and stainless steel are used as filter materials in applications requiring high temperature resistance while retaining the ability to regenerate the filter element. For example, sintered stainless steel elements are used for filtering steam in food and pharmaceutical applications....