What type of corrosion is typically responsible for degraded EMI protection in enclosed avionic equipment?

The type of corrosion typically responsible for degraded EMI (Electromagnetic Interference) protection in enclosed avionic equipment is galvanic corrosion. This form of corrosion occurs when two different metals are in electrical contact in the presence of an electrolyte, leading to accelerated corrosion of one of the metals, often referred to as the anode.

In avionic systems, components may consist of various metals used in conjunction for their respective properties. When these metals are connected electrically, galvanic corrosion can take place, especially if they are situated in environments where moisture or other conductive materials are present, providing the necessary electrolyte. The degradation of the protective coating or the base metal itself can lead to increased electrical resistance, thereby compromising the EMI shielding effectiveness.

Understanding the susceptibility of avionic components to galvanic corrosion is crucial, as it not only affects the integrity of the equipment but can also impact the reliability and performance of the entire avionic system. Ensuring that components are made from similar metals or are properly insulated can help mitigate the risks associated with galvanic corrosion.