What is intergranular corrosion?

Intergranular corrosion specifically refers to the corrosion that occurs along the grain boundaries of a metal, particularly in metal alloys. This type of corrosion is often linked to factors such as the presence of certain alloying elements, improper heat treatment, or the effects of welding. When a metal is alloyed, its structure consists of grains; these grains can become susceptible to corrosion due to localized degradation at the boundaries where the grains meet. This vulnerability can lead to structural integrity issues because the corrosion attacks areas that are critical for maintaining strength and durability.

Understanding intergranular corrosion is essential for those in the aviation industry since it can compromise safety and reliability in aircraft structures. The focus on grain boundaries is vital because this type of corrosion often goes unnoticed until significant damage has occurred, making it a serious concern during inspections and maintenance processes. This is why the answer emphasizing the formation of corrosion along grain boundaries is the most accurate representation of intergranular corrosion.