What corrosion-prone area is a prime spot for corrosion because of dissimilar metal contact between the steel pins and the aluminum hinge tangs?

What corrosion-prone area is a prime spot for corrosion because of dissimilar metal contact between the steel pins and the aluminum hinge tangs?

• A. Piano Hinges
• B. Water Entrapment Areas
• C. Electronic Connectors
• D. Rocket & Gun Blast areas

Answer: (A)

Dissimilar metals in electrical contact in the presence of an electrolyte drive galvanic corrosion. In aircraft hinges, the steel pin runs through aluminum hinge tangs, so moisture or water spray infiltrating the hinge creates a tiny electrochemical cell between steel and aluminum. Aluminum is more anodic than steel, so it will corrode preferentially at the interface around the pin while the steel remains comparatively protected. This makes piano hinges a prime spot for corrosion because the long contact surface and frequent exposure to humidity and contaminants provide both the dissimilar-metal pair and the environment needed for corrosion to accelerate. Other areas can corrode too, but the explicit combination of steel and aluminum in a hinge is the classic, high-risk scenario.

Dissimilar metals in electrical contact in the presence of an electrolyte drive galvanic corrosion. In aircraft hinges, the steel pin runs through aluminum hinge tangs, so moisture or water spray infiltrating the hinge creates a tiny electrochemical cell between steel and aluminum. Aluminum is more anodic than steel, so it will corrode preferentially at the interface around the pin while the steel remains comparatively protected. This makes piano hinges a prime spot for corrosion because the long contact surface and frequent exposure to humidity and contaminants provide both the dissimilar-metal pair and the environment needed for corrosion to accelerate. Other areas can corrode too, but the explicit combination of steel and aluminum in a hinge is the classic, high-risk scenario.