What is the consequence of moisture being trapped between metals due to fretting?

When moisture is trapped between metals due to fretting, it creates an environment that facilitates oxidation. Oxidation is a chemical reaction that occurs when a metal reacts with oxygen in the presence of moisture. In this scenario, the high friction generated by fretting motion can break down protective oxide layers, exposing bare metal surfaces to moisture and air. This exposure increases the likelihood of corrosion, as the trapped moisture acts as an electrolyte, which promotes further degradation of the metal surfaces.

The presence of moisture leads to the formation of rust or other corrosive compounds, which can significantly weaken the structural integrity of the materials involved. Understanding this process is crucial in aircraft maintenance and inspection, as it highlights the need for regular checks and preventive measures to avoid corrosion and ensure safety in flight operations.