What metal has special short-time heat properties and is used in the construction of aircraft firewalls?

• A. Aluminum Alloy
• B. Copper Alloy
• C. Stainless Steel
• D. Titanium Alloy

Answer: (D)

Firewalls must block flames and hot gases during an engine fire for a limited period while keeping weight down. Titanium alloys fit this need because they offer very high strength at elevated temperatures coupled with a low density, so the structure stays stiff without adding heavy weight. Their high melting point and protective oxide layer help them resist heat damage during the short, intense exposure of a fire. Aluminum alloys, though lighter, lose strength as temperatures rise; copper alloys and stainless steel either add too much weight or don’t balance strength and heat resistance as well for this specific role. So for the ability to withstand brief, extreme heat while remaining lightweight, titanium alloy is the best choice for aircraft firewalls.