Definition
A metal that combines readily with oxygen, nitrogen, or other elements at elevated temperatures, requiring special handling during welding, machining, or heat treatment to prevent contamination of the metal and to avoid fire or explosion hazards. Common reactive metals used in aviation include titanium, magnesium, and beryllium.
Plain English
A metal that easily reacts with the air around it, especially when hot. Because of this, working with it requires extra care to keep it from being damaged or catching fire.
Context Anchor
Seen in aircraft materials, repair, welding, corrosion, and fire-safety discussions.
Derivation
From Latin re- (back, again) + agere (to act). A reactive metal is one that 'acts back' against its surroundings — readily combining with other substances rather than staying chemically stable.
Why Pilots Care
Improper handling of reactive metals during grinding, drilling, or welding can cause fires or hidden corrosion that affects structural integrity.
Intuition Check
Reactive does not mean radioactive. Here it means chemically active: the metal can react strongly with heat, air, moisture, or other substances.
Example Sentence 1
Titanium is a reactive metal, so welding it requires shielding gas to keep oxygen and nitrogen away from the weld.
Example Sentence 2
Welders shield titanium parts with inert gas to keep the reactive metal from oxidizing during the repair.