Quick answer: aircraft-engine heat exchangers transfer heat between oil, fuel, air or other controlled circuits to manage lubrication temperature, cool compressed air, protect components and improve thermal efficiency. Material choice depends on temperature, pressure, vibration, fluid compatibility, mass and certification—not heat resistance alone.
Fuel-oil heat exchangers can cool lubricating oil while warming fuel within controlled limits. The system design must prevent cross-contamination and address pressure differences, leakage detection and icing or coking risks.
Air-to-air or air-to-liquid exchangers may cool bleed air, compressor air or accessory systems. Effectiveness must be balanced against pressure drop, size, weight and available cooling flow.
Thin walls improve heat transfer but reduce corrosion allowance and increase sensitivity to vibration, fatigue and manufacturing defects. Stainless steels, nickel alloys, titanium and aluminum alloys may be considered depending on location and duty. The final selection must follow the engine or aircraft qualification requirements.
Dimensional inspection, chemical and mechanical certification, cleanliness control, weld or braze qualification, pressure/leak testing and appropriate NDT support reliability. Generic “aerospace grade” wording is not sufficient; the material and process specifications must be stated.
For corrosion-resistant tubing requirements, review stainless steel tube and pipe options, subject to the required aerospace specification and qualification.