Electrical connectors on various aircraft undertake critical functions of signal transmission and power distribution. From cockpit avionics systems and connector harnesses to in-seat entertainment interfaces, any contact failure may trigger system-level faults. Connectors in long-term service frequently suffer from contact oxidation and fretting corrosion. Therefore, selecting a suitable anti-oxidation grease for aerospace connectors is a cost-effective safeguard for the electrical reliability of the complete aircraft.

I. Why Do Aerospace Connectors Need Anti-Oxidation Lubrication?

Connector plating is not completely immune to degradation. Oxidation usually initiates at micropores and worn areas. Surface treatments such as gold plating and silver plating can significantly reduce contact resistance, yet plating layers have inherent limitations: thin coatings may contain microscopic pores, and repeated mating/unmating together with vibration gradually wears away the plating. Once base metals (e.g. copper, nickel) are exposed to air, oxidation occurs, forming poorly conductive oxide films that raise contact resistance and attenuate signals.

Fretting corrosion arises from repeated oxidation under vibrational conditions. Aerospace equipment is continuously subjected to vibration, shock and thermal cycling. Low-amplitude fretting takes place on connector contact surfaces. Such micro-movement continuously abrades plating and exposes fresh metal surfaces, causing recurring oxidation. Oxide particles accumulate in contact zones, gradually increasing contact resistance, resulting in power loss, signal distortion, or even complete connector failure.

II. Three Core Criteria for Selecting Anti-Oxidation Grease for Aerospace Connectors

Criterion 1: Ability to isolate oxygen and corrosive media 

The core function of anti-oxidation grease is to form a protective lubricating film on contact surfaces, separating metals from oxygen, moisture, corrosive gases and chemicals. Take NyoGel 760G as an example: it features only 2% water washout loss and excellent salt spray resistance. It provides environmental sealing for connectors deployed in outdoor conditions to prevent base metal corrosion. For gold-plated connectors, the lubricating film also seals microscopic pores in plating layers to stop substrate attack while maintaining low and stable contact resistance.

Criterion 2: Ability to suppress fretting wear and reduce insertion force 

The lubricating film prevents direct metal-to-metal contact, protects contact surfaces under vibration and inhibits fretting wear. FUCHS Rheotemp 768G is specially formulated for electrical contacts to lower insertion force and prevent fretting wear. NyeTact 571H-10 is developed for electrical connectors and sliding electrical contacts to address common drawbacks of conventional greases, including high contact force, arcing and airborne contaminants.

Criterion 3: Compatibility of temperature range and materials 

Avionics equipment often operates across a wide temperature spectrum. Uniflor 8950 operates from -90°C to 225°C with outstanding oxidation resistance and good compatibility with plastics and elastomers. Uniflor 8980 maintains stable performance over the wide temperature range of -65°C to 250°C.