Powder metallurgy

Powder metallurgy (PM) technology uses powdered materials consolidated by a thermal process. Powder preparation, shaping and thermal conditions vary according to the products involved.

It is used either because it is :

• a convenient means of producing certain metals or alloys with special physical or mechanical properties (e.g. refractory metals such as tungsten, alloys or pseudo-alloys of two immiscible materials in the liquid state, such as copper and graphite, or porous parts throughout their mass);

• a relatively economical manufacturing method when a large number of parts are required.

The high moldability of powders will be exploited to obtain complex shapes, or the possibilities of diversifying the constituent elements to obtain very specific structures. In this way, processes can be designed to obtain special materials with specific physico-chemical properties, or to produce components whose shape and geometry meet specific functional requirements.

What sets this technology apart is that, unlike many other shaping processes, the shapes and dimensions are generated before the mechanical characteristics. As a result, there are some distinct differences.

Main processes :

• uniaxial oedometric compression (cold or hot) ;

• isostatic compression (cold or hot (HIP) ;

• MIM (metal injection moulder) or PIM (powder injection moulding);

• compression-free forming.

Main markets :

• mechanical parts (automotive, jet engine, watchmaking, armaments, portable electrical equipment, etc.) ;

• self-lubricating ;

• braking ;

• electrical components (connectors, magnetic components) ;

• medical (prostheses, stapler tips, brackets) ;

• tool steels ;

• filter parts ;

• nuclear fuel.

This presentation focuses on the oedometer compression process, which covers the most important markets in powder metallurgy. These markets are characterized by :

• volumes justifying the production of molds (tooling);

• complexity and precision of shapes ;

• surface quality ;

• high mechanical properties ;

• severe...