How does fretting corrosion manifest in wave springs used in high-vibration aerospace connectors, and how can it be mitigated?

Fretting corrosion occurs at the contact points between the wave peaks and the mating surface when micro-oscillations (typically 1-100 μm) are present. In aerospace connectors, vibration causes the spring to rub against the housing. This generates fine metallic debris that oxidizes and acts as an abrasive, leading to material loss and a decrease in preload. Mitigation strategies include applying a dry-film lubricant (e.g., MoS2 per MIL-L-46010) to reduce the coefficient of friction, or using a material with higher surface hardness. Additionally, increasing the spring's preload can sometimes 'lock' the surfaces together, preventing the relative micro-motion.