Abstract: A copper powder-free friction material which is made by sintering and intended for friction surfaces of couplings or brakes contains powdery and/or granular metallic and non-metallic components, at least 50% by weight of the non-ferrous heavy metal component being brass powder.

Abstract: A friction or rubbing element for clutches, brakes, bearings or the like consists of a metal ring element with at least one uneven friction or rubbing surface which is substantially rotationally symmetrical about the ring axis and comprises a spray-sintered lining directly sintered thereon. To produce this lining the ring element is arranged in a level position together with a sinter mould disposed substantially concentrically to the side of the friction or rubbing surface in such a manner as to maintain an annular gap. After filling the annular gap with sinter powder, the complete assembly is heated to sintering temperature. The sinter mould material has a coefficient of thermal expansion which in the case of an internal sinter mould is greater than and in the case of an external sinter mould is less than that of the ring element, pressure being applied during sintering by virtue of the different temperature expansion.

Abstract: A friction ring for clutches and brakes consists of an annular metal element having at least one cylindrical or conical friction surface comprising a spray-sintered friction lining. The friction linings are directly sintered onto the annular element itself, the intially planar friction surfaces being formed, after applying the spray-sintered friction linings, into cylindrical or conical shape by a non-cutting shaping process such as stamping, deepdrawing or the like. The method of producing the friction ring comprises producing an annular metal element, applying a spray-sintered friction lining on to one or both sides thereof and shaping the annular element together with the sintered linings applied thereto into a cylindrical or conical form. The shaping is performed by means of a shaping tool comprising a die and an associated plunger working on the annular element.

Abstract: Sintered friction laminae are produced by scattering metal powder on a steel substrate and then sintering the powder/substrate article in a furnace with free nitrogen in the furnace atmosphere, which atmosphere is continually renewed. The nitrogen is produced by decomposition of ammonia and diffuses into the steel substrate to harden the steel.