What condition can cause electrolytic corrosion between copper and aluminium connections?

What condition can cause electrolytic corrosion between copper and aluminium connections?

• A. Condensation reaching the connection causing electrochemical reaction.
• B. Dry air preventing corrosion.
• C. Tin-plated lugs in dry rooms.
• D. Water-free environment.

Answer: (A)

Electrolytic (galvanic) corrosion happens when two dissimilar metals are in contact and a conducting liquid link forms between them. Condensation provides just that liquid—water containing dissolved minerals and salts—that closes the circuit between copper and aluminium. In this moist environment, the different electrochemical potentials of copper and aluminium drive a current, and ions move through the little electrolytic gap, accelerating corrosion at the interface. Dry air or a water-free environment don’t supply the necessary electrolyte, so the corrosion rate stays very low. Tin-plated lugs in dry rooms reduce moisture exposure, which also minimizes the chance of electrolyte formation, so they don’t create the conditions for electrolytic attack.

Electrolytic (galvanic) corrosion happens when two dissimilar metals are in contact and a conducting liquid link forms between them. Condensation provides just that liquid—water containing dissolved minerals and salts—that closes the circuit between copper and aluminium. In this moist environment, the different electrochemical potentials of copper and aluminium drive a current, and ions move through the little electrolytic gap, accelerating corrosion at the interface. Dry air or a water-free environment don’t supply the necessary electrolyte, so the corrosion rate stays very low. Tin-plated lugs in dry rooms reduce moisture exposure, which also minimizes the chance of electrolyte formation, so they don’t create the conditions for electrolytic attack.