To ensure Slip ring can work normal that in vibration, shock and acceleration conditions, require the selected brush material has sufficient strength and good elasticity, and good conductivity, easily oxidized. Slip ring work, between the brush and the conductive ring is a relative sliding, with the growth of the working hours, the dust produced by wear can cause conductive ring and brush contact resistance increases, the rings insulation resistance becomes smaller, greatly affect the life of the transmission signal and should therefore be a reasonable choice to match the brush and conducting ring coating material, in order to guarantee good contact performance and extend the working life of friction.

Select the brush material
According to the working characteristics of the brush, the brush material should have a low resistivity, large elastic modulus, elastic hysteresis as small as possible, good chemical stability and resistance to electric corrosion resistance, good processing properties, the most important the point is that the brush material must have ultra-high wear resistance.
Most stable chemical properties of gold, but gold is very soft and can only be used as contacts plating; silver is the highest conductivity, the cheapest price of precious metals, therefore, whole or overburden silver contacts can be used for the brushes, but the disadvantage of silver contact material is resistant to cure poor, low hardness, easy to cold welding, oil transfer material tends to work in DC. Using technology can improve the mechanical properties of an alloy of gold and silver, to eliminate the above drawbacks. In improving the hardness and tensile strength, while no adverse effects on the electrical conductivity; can improve the stability of sulfates; alloy materials in most applications better than gold or silver properties, especially some of the ternary or higher alloy widely available, the ability of these alloys both sufficient anti-surface film formation, and good mechanical properties.

Select the conductive ring material
Conductive ring and brush as a dual material, its performance directly affects the reliability of the electrical contact elements and electrical conductivity. Since the conductive ring is used to match and brushes, material selection to consider when working conditions and various properties of the product brush material, in order to achieve a reasonable match, reliable performance, long service life of purpose. Conductive ring material into precious metals and their alloys and plating of precious metals and their alloys composite materials (mostly copper base alloy) categories. Both materials have good chemical stability and resistance to electrical erosion resistance, low friction factor, good processing properties. Gold, platinum, palladium base alloys high prices, and material of the conductive ring larger amount of investment will lead to cost increase. Therefore, the project size is usually chosen consistency, low price, corrosion resistance, electrical conductivity, adhesion, welding, processing technology can meet the requirement of material, surface plating process by strengthening the precious metals and their alloys, can effectively reduce and stable contact resistance, and the brush material and reasonable match.
Precious metal plating is divided into single metal plating, alloy coating, the coating composition. In recent years, the development of precious metal plating contact material very quickly, not only because it can save a lot of precious metal plating method, and plating layer hardness and electrical contact characteristics higher than the same composition of metals and alloys, the friction factor is smaller, lower electrical noise.