When working with carbon/graphite composite structures, which material is recommended for fasteners?

Using titanium or corrosion-resistant steel for fasteners in carbon/graphite composite structures is highly recommended because these materials provide compatibility with the composite's properties. The primary concern when selecting fasteners for composite materials is to avoid galvanic corrosion, which can occur when dissimilar metals are in contact with one another in the presence of an electrolyte.

Titanium is known for its excellent strength-to-weight ratio and resistance to corrosion, making it an ideal choice when dealing with composite structures. Sulfate and chloride, which are often present in the environment, can cause corrosion, so corrosion-resistant steel also serves to prolong the lifespan of the fastener assembly in such environments. Additionally, both titanium and corrosion-resistant steel maintain a good bond and compatibility with the performance characteristics of carbon/graphite composites, ensuring structural integrity and safety.

The other materials listed in the options either do not provide the necessary strength, durability, or resistance to corrosion that is critical in aviation and aerospace applications where carbon/graphite composites are commonly used.