Which type of rivet is suitable for use without any further treatment?

The correct choice is 2117-T3 rivets, which are known for their suitability for use without any further treatment. These rivets are made from a type of aluminum alloy that has been heat-treated to enhance its strength, making them ideal for various applications, especially in aircraft structures where a balance of strength and corrosion resistance is critical.

2117-T3 rivets have excellent shear and tensile strength, making them a reliable choice for structural applications. They also have good workability, which means they can be easily formed and attached without needing additional treatment like anodizing or painting for strength or corrosion resistance. This property makes them in demand in the aerospace industry, where performance and integrity are paramount.

In contrast, the other materials listed are alloy types that may require further treatment or processing. For example, 2024-T3 might require heat treatment or surface coating to enhance its properties post-manufacturing, while 6061-T6 and 5052-0 generally have different applications that may involve additional treatments to improve their performance in certain environments. Thus, 2117-T3 stands out as the most appropriate choice for immediate use in applications requiring rivets.