Conductivity of contact materials
Silver contacts
Conductivity: Silver is one of the most conductive metals, with a resistivity of about 1.59 × 10^-8 Ω·m. This makes silver one of the preferred materials for toggle switch contacts, especially in applications that require high conductivity.
Application effects: Silver contacts perform well in high-frequency and low-voltage applications, such as audio equipment and precision instruments. However, silver is easily oxidized and sulfided to form non-conductive silver oxides and silver sulfides, which affect contact performance.
Gold contacts
Conductivity: Gold is slightly less conductive than silver, with a resistivity of about 2.44 × 10^-8 Ω·m, but it is still an extremely conductive metal.
Application effects: Gold has excellent anti-oxidation and anti-corrosion properties, so it is widely used in fields that require high reliability and long-term stability, such as communication equipment, aerospace, and medical equipment. Although gold is more expensive, its excellent performance in harsh environments often makes it the best choice.
Copper contacts
Conductivity: The resistivity of copper is 1.68 × 10^-8 Ω·m, and its conductivity is second only to silver. It is a commonly used material in electronic devices.
Application effect: Copper contacts are cost-effective and suitable for most common electronic devices. However, copper is easily oxidized to form copper oxides, which significantly increases the contact resistance and affects the switching performance. Therefore, copper contacts usually require electroplating to improve their oxidation resistance.
Wear resistance and corrosion resistance of contact materials
Silver contacts
Wear resistance and corrosion resistance: Silver has general wear resistance and does not perform as well as gold and some alloy materials in high-wear environments. In addition, silver is easily oxidized and sulfided, especially in sulfur-containing environments, and needs to be protected by electroplating or coating technology.
Application environment: Suitable for indoor, dry environments, and low-load application scenarios, such as consumer electronics and low-power industrial equipment.
Gold contacts
Wear resistance and corrosion resistance: Gold has excellent wear resistance and corrosion resistance, and performs well in humid, high-temperature, and corrosive environments. It is not easy to form oxides on the gold surface, which ensures long-term and stable conductivity of the contacts.
Application Environment: Widely used in high-end electronic devices, precision instruments, and critical applications in harsh environments, such as military and aerospace equipment.
Copper Contacts
Wear and Corrosion Resistance: Copper has good wear resistance, but poor corrosion resistance and is easily oxidized. Therefore, copper contacts are usually silver-plated or gold-plated to improve their corrosion resistance and conductivity.
Application Environment: Suitable for most standard industrial environments, but requires additional protection in high humidity and highly corrosive environments.