This has two main reasons:

(1) saving costs compared to alternative processes, or

(2) special attributes attainable by the PM-route only.

Saving costs plays a significant role within the following uses:


Structural (or mechanical) Parts:

This is the undoubted larger group.

Parts on iron base are the main section, but significant amounts of aluminium, brass, bronze and copper parts are produced as well as some titanium and beryllium. Although such parts have advantage over forgings in dimensional accuracy the main reason for their use is the economic thought. Within the past few years it has become possible to produce sintered parts, like with Hot Isostatic Pressing Services / Heißisostatisches Pressen with properties equal to or even superior to those of parts made in more traditional ways. There have been developments as well as in the materials as in modifications in the whole standard process of production.

Concerning parts with special characteristics the following examples shall be given:

pmSource: EPMA

Porous Materials: Most forms of metal are porous to some extent, sintered metals, poduced with a Hot isostatc Press (HIP) or also in some cases with a Cold Isostatic Press (CIP) even more, but here we have a process of producing parts having a significant adjusted porosity for several required purposes. The main products of this group are filters and oil-retaining bearings also referred to as self-lubricating bearings.

The following products cannot be produced satisfactorily by alternative processes:

Refractory metals have extremely high melting points such as molybdenum, tungsten, niobium, tantalum and rhenium. They are very difficult to produce by melting and casting plus are very brittle during cast state. A sintered powder compact can be deformed at a suitably elevated temperature mechanically. Then it gradually develops a microstructure with preferred orientation that gives the meanwhile dense material useful elasticity even at ambient temperatures.


The basic procedure in the manufacture of PM consists of:

(1) The metal powder(s) has/have to be mixed with a suitable lubricant.

(2) This mixture is loaded into a die or mould before pressure is applied. This result is called compact, which requires sufficient cohesion enabling it to be handled safely as well as being transferred to the next stage. Such compacts are also called green meaning unsintered.

(3) Now the compact is heated within a protective atmosphere at a temperature below the melting point of the main constituent. The powder particles will weld together and confer sufficient strength to the object for the user’s requirements. This process is called sintering. A minor constituent becomes molten at the sintering temperature sometimes which process is called liquid phase sintering. The amount of liquid phase has to be limited to ensure the part retains its shape.

The second and third step can also be combined in form of a compaction done at an elevated temperature so that sintering occurs during the process. This is called termed hot pressing, or pressure sintering.

This process can be performed in various variants.

Loose powder sintering means that no pressure is used but the powder is sintered within a suitable shaped mould.

Powder Metallurgy

Powder Metallurgy (PM) is a form of sintering. Individual engineering components are produced directly by the process and referred to as sintered components / parts, or PM parts.

Processed products also can be generated from powder and scientifical developments of great industrial potential are in a steady process.

In order to producing a compact having sufficient cohesion enabling it to safe handling the powder is compressed, usually in a container, and heated afterwards to a temperature below the melting point of the main constituent. Due to this process the individual particles weld together and confer sufficient strength on the material for suitable use. This heating step is referred to as sintering.