What are the precautions for material selection of bimetal contact rivets

In modern electrical connection technology, bimetallic contact rivets are key components, and their performance directly affects the reliability and stability of the overall system.

Conductivity and resistivity
Conductivity is the core performance indicator of bimetallic contact rivets. In the material selection process, the conductivity of the metal is particularly important, especially in the rivet contact part. Silver is widely used in high-end electrical connections due to its excellent conductivity. However, the high cost of silver and its relatively low hardness make it impractical in some cases. For this reason, alloys of silver and other metals such as copper are usually used to optimize conductivity and economy. Copper, as a metal with good conductivity, has a relatively low cost, but in extreme environments such as high temperature or humidity, its oxidation rate is fast, which may lead to a decrease in conductivity. Therefore, the selection of materials should comprehensively consider the particularity of the application environment to ensure that the cost is controlled while meeting the conductivity requirements.

Corrosion resistance and environmental adaptability
Corrosion resistance is a key factor in ensuring the long-term and stable operation of bimetallic contact rivets in various environments. Rivets are often exposed to corrosive environments such as salt spray, humidity and high temperature in electrical connections. Therefore, it is crucial to select materials with excellent corrosion resistance. Nickel is usually used as a coating material for bimetallic contact rivets due to its excellent corrosion resistance to enhance the corrosion resistance of rivets. In addition, refractory metals such as tungsten and molybdenum are suitable for electrical connections in extreme environments such as high temperature and high pressure due to their high melting point and good chemical stability.

Mechanical properties and strength
Mechanical properties are one of the important indicators for evaluating bimetallic contact rivets. Rivets need to withstand a variety of mechanical stresses such as insertion and extraction force and shear force, so it is crucial to select materials with high strength and hardness. Although soft metals such as copper and silver perform well in electrical conductivity, they have low mechanical strength and are prone to deformation or wear. In contrast, hard metals such as tungsten and molybdenum have relatively poor electrical conductivity despite their high strength. Therefore, the design of bimetallic contact rivets usually uses soft metal as the contact surface to improve electrical conductivity, and combines hard metal as a supporting layer to enhance mechanical strength, thereby achieving the best balance of performance.