What is the purpose of grease for electronic connectors? How to use grease lubrication?

Larger current electrical contacts are generally based on copper materials, while small current contacts are based on silver materials. Electrical contact grease separates the contact surface from the surrounding medium, preventing the contact from contacting with oxygen, sulfur, water and other corrosive substances to generate a rust film. Electric contact grease must have insulating properties, but also requires the two contact grease in the contact closed state must also have energizing properties. The energizing mechanism is the metal contact part of the current through the very thin oil film energized, electric contact grease lubrication is from mixed lubrication to boundary lubrication. When the oil film becomes thicker, from elastic fluid lubrication to fluid lubrication, metal contact disappears, the oil film is not energized.

On the contrary, when the oil film is too thin, it becomes boundary lubrication, wear increases, and contact life is shortened. Therefore, a good electric contact grease should maintain the appropriate thickness of the oil film. Lithium composite compared with other thickeners, insulation degradation life is long, this is due to lithium composite groove formation is very strong, contact surface is not easy to learn the existence of leakage of grease's sake. However, its performance in inhibiting wear is poor. Sliding contacts at low temperatures sometimes do not electrify the phenomenon, this phenomenon is known as intermittent electric shock or low-temperature jumping phenomenon (contacts in the closed state of no current through the phenomenon), this is a low-temperature lubricating grease to solve the problem. The frequency of intermittent vibration increases with the viscosity of the base oil movement, and when the viscosity of the base oil movement increases, intermittent vibration is more likely to be generated and the energizing property decreases. The deterioration of energizability at low temperature can be attributed to the increase in viscosity of the oil, the thickening of the oil film, the disappearance of the metal contact area and the difficulty of passing the electric current through the oil film.

Volume resistivity is a key indicator of electrical contact grease. Volume resistivity is too large, affecting the electrical contacts conductive effect resistivity is too small, easy to produce arc, affecting the service life of the electrical contacts. If you want to increase the volume resistivity of the electrical contact grease, you can use a larger resistivity of the base oil, or improve the base oil refining depth; to increase the electrical conductivity of the electrical contact grease, you can add organic conductive agent or other conductive micropowder, so as to achieve the purpose of adjusting the resistivity.