Sintered metal friction components are particularly useful for heavy-duty applications, e.g. aircraft brakes, heavy machinery clutch and brake linings etc.
They consist essentially of a continuous metal matrix, into which varying amounts of non-metallic friction generators, such as silica and emery are bonded.
- Compositions tend to be complex in view of the characteristics required, and may include copper, tin, iron, lead, graphite, carborundum, silica, alumina, emery and asbestos substitutes.
The sintered material has a high thermal conductivity , and may be used over a wide range of temperature.
- Satisfactory performance figures have been reported for copper-based materials, operating at surface temperatures up to 800°C and from iron-based materials up to 1000°C.
- The resistance to wear is superior to resin-bonded materials, and therefore, permits the use of components of thinner section.
Because of the large surface area, and this thinness of section, the components are relatively weak.
- Mechanical strength is imparted by bonding the friction element to a steel backing-plate, either by brazing or welding, or by sintering the two components together under pressure.
- Compared with solid phosphor bronze or aluminium bronze friction elements, the sintered material offers many advantages.
The most important is probably the much wider range of friction characteristics which can be obtained from variations in the dispersion of non-metallic particles.