What does fretting primarily cause in terms of metal interaction?

Fretting primarily causes oxidation to form between metals due to the relative motion or vibration that occurs between two surfaces in contact, often under load or stress. This micro-motion can lead to the wear of protective surface coatings and create small abrasive particles that contribute to the formation of oxide layers, facilitating a process known as fretting corrosion.

When two metal surfaces experience fretting, the continuous movement can disrupt the oxide layers, exposing fresh metal surfaces to the environment, allowing for oxidation processes to occur. The resulting oxides can adversely affect the integrity of the joint and lead to further degradation of the metal surfaces. Understanding this interaction is crucial in the maintenance and inspection processes, particularly for components subjected to vibration and load cycles.