Not just goldsmiths and jewelers: silver is also useful for allowing the conduction of current and, in particular, it is used in the industrial production of silver electrical contacts. Let’s take a look at the most effective types, applications and metal alloys.
Silver electrical contacts: pros and purposes
Silver electrical contacts are widely used in the electronic and electromechanical industries to allow low voltage switching devices to work. Silver contacts have a high conductivity level and, when installed in an electrical circuit between two metal surfaces, they allow the current to pass from one point to another.
For example, it’s common to find silver electrical contacts in relays and remote switches, thermostats and regulators, switches and micro-switches, precision tools and, in general, in all standard appliances used in home, or for lighting and temperature purposes.
What are the main types of electrical contacts
There are almost infinite types of electrical contacts available on the market, both standard or customized models to respond to specific requirements. Rivets, stamped or blanked contacts, disc or spring contacts, terminals and connectors – to mention just a few.
We can however classify silver contacts based on their composition:
- Solid contacts: made entirely of silver or a silver alloy, highly reliable and efficient but typically more expensive;
- Bimetal or trimetal contacts: made of silver and copper on two or three layers, they are cheaper and ensure good performance levels;
- Brazed contacts: composed of silver plates welded together with other metals such as copper, brass, iron, gold or miscellaneous alloys.
Silver alloys in the production of electrical contacts
When producing silver electrical contacts, it is necessary to consider which metals and alloys are most suited to the destination of use. For example, manufacturers of electrical contacts with a low breaking capacity can opt for silver-copper alloys, whilst for contacts with a high breaking capacity, alloys with high melting points are typically better, such as silver-tungsten, silver-cadmium, silver-nickel or silver graphite alloys.
The most commonly used alloys by silver electrical contact manufacturers are:
- Silver 999 (Ag, pure silver)
This type of silver is definitely more expensive but has high electrical-thermal conductivity and high mechanical resistance in relation to welding and combustion. - Silver-Nickel (AgNi)
Alloy composed of silver (85-95%) and nickel (15-5%), which improves material hardening and electrical load resistance. Silver-nickel contacts are widely used as they are cheaper, deliver very good levels of performance and resistance against wear and fatigue. - Silver-Cadmium Oxide (AgCdO)
An alloy commonly used in the past for electrical contacts given its excellent performance in handling short and high current peaks; more recently it was classified as a material that is not environmentally sustainable, with potential carcinogenic and toxic effects. - Silver-Tin Oxide (AgSnO2)
This is produced in the same way as silver-cadmium by means of pulverization and sintering, but unlike the previous alloy, this is not a toxic material, and was developed more recently, all while achieving excellent performances on high loads.
Advanced machines for precious metal processing
Multi-stand rolling mills make it possible to easily work with different metals and alloys, guaranteeing excellent cost-efficiency and performance levels: these machines are ideal for the production of silver contacts, where a precise control over the metal processing is required.
Invimec is a company specialized in the production of machines used to process gold, platinum, silver and other metal alloys, precious and non-precious. Our rolling trains for strips and plates are able to achieve maximum precision when reducing materials and guarantee total control over the production process.
Manufacturers choose us as they have the option to customize the design of the machines: we share all of our know-how and expertise to achieve the most ambitious projects. Contact us and find out more about our silver electrical contact production lines.
