Parts produced using powder metallurgy are becoming increasingly important, particularly in the automotive industry. In order to produce self-lubricating sintered parts, metal powders are mixed with small amounts of waxes and graphite, and the powders are pressed under high pressure to form so-called “green compacts”. Graphite reduces the wear of the pressing tool and lubricates the powder mixture during compaction. In the course of the sintering process, in which the green parts are heated to just below the melting point, the material is compacted further. Fine graphite diffuses into the layer at the edge of the metal, increasing the mechanical strength of the workpiece and at the same time maximising its lubricating effect.
