Final answer:
Intergranular corrosion significantly weakens the structural integrity of aluminum alloy parts by compromising the protective oxide layer, thus reducing the material's reliability.
Step-by-step explanation:
The effect of intergranular corrosion on aluminum alloy parts is that it weakens the structural integrity of the parts. As aluminum is easily oxidized, the protective oxide layer normally prevents corrosion of the interior material. However, when intergranular corrosion occurs, this layer is breached, leading to a weakening of the metal from the inside out. Methods like anodizing aluminum can strengthen the oxide layer, but once the process of intergranular corrosion begins, the structural integrity of aluminum alloys is compromised, making them less reliable in their applications.
Common methods to slow down corrosion include preventing exposure to oxygen and water, cathodic protection using more reactive metals, and the use of metal alloys that are less prone to corrosion. Unfortunately, once intergranular corrosion sets in, these methods become less effective at preserving the aluminum alloy's structure.