Analysis of the Principle and Manufacturing Process of Trimetallic Rivet-Type Contact Technology

In low-voltage electrical appliances, relays, and switching systems, the material of electrical contacts directly affects the conductivity, wear resistance, and service life of the equipment. With the continuous fluctuations in the price of precious metal materials, the industry has begun to seek more efficient ways to utilise materials. Among these, trimetallic contact structures have gradually become one of the important technological routes. These Trimetal Silver Contacts achieve a balance between performance and cost by combining silver alloys with copper-based materials, gaining widespread attention in the field of electrical connections.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Traditional solid silver contacts provide excellent conductivity in many applications, but their material cost is high. By adopting a three-layer composite structure, that is, combining silver alloy materials at both ends of a copper substrate, the amount of precious metals used can be significantly reduced while ensuring electrical performance. This Trimetal Electrical Contacts structure not only maintains stable contact resistance but also reduces precious metal consumption by approximately 30% to 70% without affecting the reliability of electrical operation, thereby improving the economics of the product.

 

In the structure of electrical contact products, trimetallic rivet contacts are typically composed of three layers of materials: silver alloy-copper-silver alloy. This structure is also known as Ag/Cu/Ag Tri-metal Contact Rivets. The silver layer primarily provides conductivity and resistance to arc erosion, while the copper core provides mechanical support and thermal conductivity. By rationally designing the composite layer ratio, material utilization efficiency can be improved while maintaining excellent electrical performance.

 

In practical applications, these Trimetal Contact Rivets are commonly used in electrical equipment such as relays, thermostats, and microswitches, and are particularly suitable for structures requiring double-sided conductive contacts. Compared to single-layer or double-layer contact structures, the triple-composite structure can form stable conductive surfaces on both sides, thus offering a significant advantage in electrical systems requiring double-sided contacts.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

From a manufacturing perspective, the core technology of triple-composite contacts lies in the layer bonding method. These products typically employ cold pressure welding technology for bonding. Cold pressure welding is a form of pressure welding that does not require heating the material during processing. Instead, high pressure causes plastic deformation of the metal, thereby breaking down the oxide film on the material surface and allowing the pure metal surfaces to directly contact and achieve atomic-level bonding. Tri-metal Rivet Contacts manufactured using this process exhibit excellent mechanical strength and electrical stability.

 

During the cold pressure welding process, when two metal surfaces are compressed to a very small gap, the electron clouds between atoms overlap and form metallic bonds, thus achieving material bonding. This principle prevents the formation of a significant heat-affected zone in the multilayer region of Electrical Trimetal Rivet Contacts, thereby maintaining the original conductivity and corrosion resistance of the material. Simultaneously, the cold pressure welding process reduces welding stress, making the contact structure more stable.

 

The structural design of a triple-layer composite contact typically includes a head silver layer and a foot silver layer. The head silver layer bears the main responsibility for conductivity and arcing during contact operation, while the foot silver layer is used for connection with the conductive structure.

 

During manufacturing, the silver layer and the copper substrate form a bonding surface through plastic expansion; this structure is also known as AgCuAg Trimetal Contacts. By properly controlling the material deformation ratio, the multilayer bonding strength can be ensured to meet industry standard requirements.

 

In some specialised structures, to ensure the silver layer on the feet meets the requirements for cold-press welding, a ring-expansion technique is employed in the manufacturing process. This technique increases the material expansion ratio through localised plastic deformation. This method is commonly used in the production of three-compound contacts, achieving stable structural forming while maintaining weld strength.

 

In terms of equipment design, the production of Three Compound Contacts typically utilises automated cold heading equipment. This equipment uses a motor-driven crankshaft and cam system to automate multiple processes, including material shearing, feeding, compound welding, and forging. This method enables continuous production, allowing Trimetal Electrical Rivets to achieve a manufacturing efficiency of thousands of pieces per hour.

 

The design of the cam mechanism is particularly critical in automated equipment. A conjugate cam system ensures synchronization between feeding, shearing, compounding, and forming actions, thus preventing material misalignment or stress concentration during production. This precision motion control technology is especially important for manufacturing high-precision electrical contact products such as Trimetallic Relay Contacts.

 

To ensure product quality, the contacts after production require testing for the strength of the multilayer bond. A common testing method is the flattening test, which involves compressing the contact head and feet to half their original diameter, then observing the cracking at the interlayer interface under a microscope. High-quality Trimetal Moving Contacts maintain a stable bonding interface even after flattening, with crack lengths far below industry standard requirements.

 

In modern electrical equipment, these Trimetal Moving Electrical Contacts are widely used in relays, circuit breakers, thermostats, and power switches. Their structure simultaneously meets requirements for conductivity, arc resistance, and mechanical strength, making them crucial in the switching equipment field.

 

With the development of new energy, electric vehicles, and energy storage systems, electrical equipment places higher demands on contact performance. High-precision Trimetal Silver Electrical Contacts maintain stable electrical connections under frequent switching and high-load conditions, thereby improving the overall operational reliability of electrical systems.

 

In practical electrical switching applications, contacts need to withstand various operating conditions such as arcing, mechanical shock, and temperature rise. Therefore, the design of high-performance Electrical Switch Trimetal Contacts requires not only consideration of material composition but also optimisation of composite structures, surface shapes, and processing precision to ensure long-term stable operation.

 

The development of three-layer composite contact technology provides an important direction for the economical use of electrical contact materials. Through rational design of material structure and manufacturing processes, the amount of precious metals used can be reduced while maintaining electrical performance, making Trimetal Silver Electric Contact a promising candidate for future applications in electrical equipment manufacturing.

 

 

 

With the development of power equipment, intelligent control systems, and the new energy industry, the demand for highly reliable electrical contacts continues to grow. Based on mature composite material technology, three-layer composite contacts can significantly reduce the amount of precious metals used while ensuring conductivity and arc resistance, becoming an important solution for modern electrical connection systems. Multi-layer composite contact structures, represented by Multi-layer Silver Contacts and Three Compound Rivets, are widely used in relays, circuit breakers, contactors, and various electrical switching devices.

 

In practical product applications, high-quality Trimetal Rivet Contacts not only improve the switching life of equipment but also effectively reduce contact resistance and heat loss during system operation. Through precision manufacturing processes and strict quality control, electrical contact assemblies can meet the stringent reliability requirements of industrial automation, power systems, and new energy equipment, providing stable and reliable conductive connection solutions for various electrical devices.