Final answer:
Galvanic corrosion can occur when aluminum pieces are attached with steel bolts, causing the aluminum to corrode due to their different electrode potentials. Prevention methods include the use of sacrificial anodes or coatings to isolate the metals.
Step-by-step explanation:
When aluminum pieces are attached with steel bolts or screws, a form of corrosion known as galvanic corrosion can occur around the fasteners. This is because aluminum and steel have different electrode potentials, making them susceptible to galvanic reactions when in contact, especially in the presence of an electrolyte like water. Over time, this can lead to accelerated corrosion of the less noble metal, which is usually the aluminum.
Galvanic corrosion is a type of REDOX process where one metal becomes the anode and corrodes at an accelerated rate while the other becomes the cathode and is protected. Preventing this type of corrosion can be done by isolating the two metals from electrical contact or by using a sacrificial anode, such as zinc or magnesium, which will corrode instead of the aluminum or steel. Additionally, coatings such as paint or a non-conductive sealant can help prevent the electrolyte from contacting the metal surfaces.