Metal fasteners used with carbon/graphite composite structures must be made of which material?

Metal fasteners used with carbon/graphite composite structures should be made of titanium or corrosion-resistant steel due to their compatibility with composite materials and resistance to galvanic corrosion. Carbon/graphite composites can react with metals such as aluminum and standard steel, leading to corrosion and degradation of both the fastener and the composite structure.

Titanium and corrosion-resistant steel are not only strong and lightweight, but they also possess properties that prevent corrosion from occurring when in contact with carbon/graphite materials. This compatibility is crucial in ensuring the longevity and integrity of the aircraft structure. Using materials that do not react adversely with the composites is essential for maintaining structural integrity and safety in aviation applications.

Materials like plastic composites, while lightweight, do not provide the necessary strength and durability required for fasteners in demanding aerospace environments. Therefore, titanium or corrosion-resistant steel is the optimal choice for fasteners in these applications.