What is generally used in the construction of aircraft engine firewalls?

The construction of aircraft engine firewalls typically utilizes stainless steel due to its superior properties that are essential for this application. Firewalls are critical components that serve as a barrier to protect the aircraft structure and crew from the intense heat and potential fire hazards that can arise during engine operation or in case of an engine failure.

Stainless steel is favored because it has excellent heat resistance and structural integrity, allowing it to withstand high temperatures without losing strength. Additionally, stainless steel has good corrosion resistance, which is important in aviation where materials are subjected to various environmental conditions. Its durability ensures that the firewall can provide reliable performance throughout the aircraft's operational life.

Other materials, while they may have their own advantages in different contexts, do not meet the stringent requirements for a firewall. For instance, aluminum is lighter but lacks the high-temperature performance necessary for a firewall application. Plastic composites, although lightweight and resistant to corrosion, may not provide the drag-resistance or temperature tolerance needed. Magnesium alloys, while they are lightweight, have lower melting points and are prone to fire hazards when exposed to high temperatures, making them unsuitable for critical heat-resistant structures like firewalls.