Metallized Carbon Corporation has announced that it produces Silver Metcar, a silver impregnated, carbon-graphite material useful for electrical applications that require low resistance, low voltage drop, and low electrical noise. The material is suited for DC motor brushes, non-welding electrical contacts, and rotary slip ring brushes or contacts in air traffic control radars, telecommunications systems, and satellite communications systems.
Low noise slip rings assemblies, known as rotary joints, microwave rotary couplings, and RF rotary joints, are used to transmit minute electrical signals in rotating equipment like microwave antennas, radar receivers, sonar receivers, rotating thermocouples read-outs, and rotating strain gauge read-outs.
“With the growth of in-flight and at-sea television and internet service, we are seeing a huge increase in demand for the material for use in antennas used to track satellites,” said Matthew Brennan, COO of Metcar. “Ships, aircraft, rail systems, and other applications that require low electronic interference will find that Silver Metcar is an excellent choice.”
The carbon-graphite in Silver Metcar provides self-lubricating properties and the pure silver provides high and constant electrical conductivity. The material is corrosion resistant, dimensionally stable and has a heavy overload capacity. Additives to the carbon-graphite base material improve its self-lubricating properties in the dry atmospheres that occur at high altitude and in space. Silver Metcar cannot melt or weld to another metal surface because the carbon-graphite base material will not melt. It can be silver plated so that it can be easily soldered to metal parts such as leaf springs or conventional brush holders.
To make the Silver Metcar materials, solid carbon-graphite base materials, in rings or blocks, are submerged in pure, molten silver and the silver is forced into the porosity of the carbon-graphite material using extremely high gas pressure. Most of the Silver Metcar grades contain approximately fifty percent silver by weight. X-ray inspection is used to ensure that each Silver Metcar part is uniformly impregnated with silver.