POWDER-METALLURGY

After having recalled the various modes for preparing powders and the main steps of the process (compression and sintering in solid or liqui d phase), the energies susceptible of controlling the evolution of the considered systems are discussed. The devised mechanisms make it poss ible to account for the formation of junctions between the particles a nd the progressive elimination of porosity. The systems studied have b etter mechanical properties as well as special using properties. Many possibilities are offered for materials with mechanical use (metallic, hard, compound,... alloys) or with a special finality (controlled por osity, friction, electric contacts, magnetic materials, ...).