Which metal type is the worst affected by corrosion?

Which metal type is the worst affected by corrosion?

• A. Aluminium alloys
• B. Stainless steel
• C. Magnesium alloys
• D. Titanium

Answer: (C)

Magnesium alloys are the most vulnerable to corrosion because they’re highly electrochemically active and form only a thin, easily damaged protective film. In moist or salty environments, such as humidity, rain, or salt spray common in aviation, magnesium oxidizes rapidly and hydrogen gas can evolve, leading to fast material loss. It’s also very anodic, so when it’s in electrical contact with more noble metals in an electrolyte, it tends to corrode preferentially (galvanic corrosion). By comparison, aluminium alloys develop a relatively protective oxide layer that resists corrosion (though they can pit in chloride environments), stainless steel relies on a robust chromium oxide film, and titanium forms a very stable protective oxide—so these materials resist corrosion far better than magnesium.

Magnesium alloys are the most vulnerable to corrosion because they’re highly electrochemically active and form only a thin, easily damaged protective film. In moist or salty environments, such as humidity, rain, or salt spray common in aviation, magnesium oxidizes rapidly and hydrogen gas can evolve, leading to fast material loss. It’s also very anodic, so when it’s in electrical contact with more noble metals in an electrolyte, it tends to corrode preferentially (galvanic corrosion).

By comparison, aluminium alloys develop a relatively protective oxide layer that resists corrosion (though they can pit in chloride environments), stainless steel relies on a robust chromium oxide film, and titanium forms a very stable protective oxide—so these materials resist corrosion far better than magnesium.