Electrical contacts are a vital part of our lives. They’re found in nearly everything that has a switch. They control the flow of electricity throughout the equipment. Electrical contacts need to be highly resilient to prevent the transfer of material from one contact to the other. If the contacts transfer material, eventually, they will join and no longer function as a switch. Contacts can be made with a variety of materials and in a number of styles to suit your specific needs, such as brass or silver electrical contacts. Welded electrical contacts are a great option for meeting the needs of your device. Here are a few of the different options.
The sort of electrical contacts you will need for your equipment will vary widely depending upon a number of different factors. If it’s a brazed contact, this simply means that it’s a machined part, which has had a silver plate welded onto it. Contacts and assemblies are used for both industrial and commercial needs. Indeed, you’d be hard pressed to find any industry which doesn’t rely on contacts at some point, whether for construction and assembly, or even during research and development. Both aerospace and automotive companies make extensive use of these parts, but those are just two obvious and well-known examples.
Silver’s high thermal and electrical conductivity make it an ideal contact material for contact applications—in fact, it has the highest electrical and thermal conductivity of all the metals. Pure silver, however, is susceptible to mechanical wear; it has a low softening temperature; it is susceptible to welding; and it can cause total failure in switching devices. Silver, therefore, is often mixed with other metals to create various silver-based contact materials. Different contact applications have different contact material requirements, and for that reason, there are a variety of different silver-based contact materials. Each silver-based contact material has its distinct advantages. Knowing the intended application of the silver-based contact materials will give you the opportunity to select the most advantageous one.
When it comes to electrical contacts, there are several popular methods of fusion. Most people are familiar with soldering, fusion welding, and adhesive bonding. While these are often the appropriate methods to use, brazing is an often-overlooked option.
Brazing is the process of fusing two metals at a much higher temperature than is ordinarily used. Specifically, the metals being joined together are heated at over 100 degrees above the typical temperature welding temperature. In some cases, brazing is an ideal choice for electrical contacts.
When designing a device or switch that calls for electrical contacts, it’s important to know what metal characteristics and properties you need for optimum performance. Choosing the right base materials will ensure that the contacts in your product will last the life of your product. A good electrical contact manufacturer will work closely with you to determine your exact needs and recommend the perfect electrical contact for you. They can also let you know if there are any concerns for your specific application.
Electrical contacts are an important part of any electrical device. They’re especially important for switching devices as they must remain in good physical and electrical shape for the life of the product. If they wear out too quickly, the product’s useful life will be shortened. Contact materials must exhibit a number of properties to work well and withstand the process of completing and breaking the electrical circuit. Some of those properties include high arc erosion resistance, high resistance against welding, and good arc extinguishing capability. Let’s look at a few excellent choices for electrical contact materials.
An alloy is a combination of two or more metals that is better than each individual metal on its own. Electrical contact manufacturers can mix metals in such a way to take advantage of the properties for both, while minimizing the negative properties of each individual metal. The result is an alloy that can be customized for your specific needs, ensuring that it will last for as long as necessary.
Composite materials are similar to alloys but typically use materials other than metals as part of the blend. Composites are particularly valuable for situations that utilize higher electrical current. Composites can be made to better resist and withstand the tendency of high electric current to arc and weld contact surfaces together. Composites are typically made through a sintering process to ensure that the materials are evenly distributed throughout the contacts.
The selection of contact materials for your electrical contact assemblies is an incredibly important part of the planning process. It’s always advised that you discuss the application requirements with an engineer or other professional as early in the design process as possible. Of course, depending upon your specific needs, there could be multiple options available in terms of the materials to be used. Each contact material will obviously come with its own pros and cons, whether that’s a tendency toward welding or “sticking,” or simply affordability. There’s also the concern of whether or not you’ll require UL or IEC approval. To learn a bit more about the different materials used in manufacturing electrical contact assemblies, you can continue reading below.
Also known as AgW, silver tungsten is a popular material for use in both large air and oil circuit breakers. It’s known for having a high resistance to arc erosion. It’s also a common choice for re-closures, line disconnects, and both high current contactors and switches. Thanks to its resistance to welding, it can also serve as a good shorting contact. Composites of silver tungsten that contain more silver are used quite often in circuit breakers and in high current contactors.
Commonly known as CuW, copper tungsten is also a very popular contact material. It’s known for being heat-resistant, ablation-resistant, easy to machine, and it’s both highly thermally conductive and electrically conductive. Copper tungsten can serve as an excellent material for switches and contacts for oil-filled devices. Thus, copper tungsten is a material commonly found used in the fossil fuel industry, as well as related industrial and commercial fields. You may also find it used in some oil, gas, or even air circuit breakers.
Sometimes shown as AgC, silver graphite is popular for many electrically conductive applications. It’s also known for having the best anti-welding properties of all contact materials. Because it has the best protection against contact welding, it’s an excellent choice for closed contacts under short circuit conditions. It’s also known for having low contact resistance and low erosion. For industrial purposes, silver graphite is excellent for circuit breakers, but it’s also effective for residential circuit breakers.
This is by no means an exhaustive list. Putting together the best electrical contact assemblies always necessities identifying the appropriate materials, so it’s always recommended that you discuss your application requirements at length before making a final decision.
Rivets used as electrical contacts are often used in low to mid-power switching applications. Checon recognizes that certain devices are best suited for a contact rivet design and we support rivet production by supplying wire to our rivet manufacturing affiliate in India as well as maintain manual and automated rivet insertion capabilities to produce assemblies in both the U.S. & India. We also recognize that there are often opportunities to move to low cost, high-reliability alternatives such as in-press wire welding or tape welding. Checon has assisted numerous customers in their design and cost out processes to help them better understand these options and appropriate application. To learn more about how electrical contact rivets are manufactured and utilized along with a more detailed explanation of the alternative cost-out opportunities, please continue reading.
Rivet Production & Assembly
Since contact rivets are formed by cold forming and brittle material can cause cracking during this process, Checon recognizes and meets the standards that the manufacturing of a solid or bi-metal contact rivet requires with consistently ductile contact material. The cold forming process can produce several different contact shapes, the most common being round with a spherical radius. Solid silver contact rivets can be produced in a variety of materials including fine silver, AgNi, AgCdO, & AgSnO. Composite bi-metal rivets are often used to save on precious metal content and expense depending upon the material system and application needs. Copper is commonly used as the base shank material. Rivet insertion to produce contact assemblies at Checon can be accomplished manually or by an automated process. Staking is carefully monitored and repeatable to ensure proper seating of the rivet with the required twist-out torque requirements.
Alternatives to RivetsChecon’s In-Press Wire & Tape Welding operation offers a low-cost option when compared with many riveted designs. High speed, one operation, in-press welding is a core competency at
Checon’s In-Press Wire & Tape Welding operation offers a low-cost option when compared with many riveted designs. High speed, one operation, in-press welding is a core competency at Checon allowing us to develop the most consistent, high quality welded contact assemblies in the industry. By connecting our weld head design to a large bed, high-speed vertical press via an innovative actuator design, we can dramatically increase production speeds to up to 400 assemblies per minute. Both electronic & mechanical shear testing is conducted on each contact before each welded contact moves into a Checon designed Class A progressive stamping die for coining of contact shape and stamping into a final contact assembly.
For more information on how Checon can help you maximize your contact and contact assembly performance while minimizing your costs, call Paul Thomsen directly at (508) 809-5159-office, (508) 801-2417-mobile, or, email him at email@example.com. Checon also offers an on-line live chat via our website at www.checon.com.
Although you may not realize it, electrical contact tapes are present in many kinds of electrical equipment. Electrical contacts are used in circuit breakers, switches, timers, and many kinds of wires. From to your kitchen to your entertainment system, electrical contact materials are making things tick all over your home, but you might not know how they work. Keep reading to find out.
Contact tapes are overlaid and welded onto electrical equipment to ensure the effectiveness of electrical flow. These tapes contain a cap of precious material, which is needed for the electrical device to function. Also, they have a base of non-precious metal which works to support the cap and facilitate attachment. By precisely controlling the thickness of the tape, the conductivity of the equipment can be maximized, while providing protection during the welding process. Electrical contacts provide many benefits during the welding process, and there are several companies that produce these materials.
Producers of electrical contact tapes sell to both individuals, as well as businesses that require this tape for their operations. Many electrical contact manufacturers also specialize in producing metal and plastic parts that can be used in electrical manufacturing. On the other hand, a company like the Checon Corporation specializes exclusively in electrical contact materials, working to create the most high-performing materials possible.
Checon offers a wide variety of contact materials. They also offer to fabricate and customize contact materials, depending on your specific needs. This guarantees the contacts you order will be the most effective for your specific application. Finally, Checon uses in-house development programs and electrical tests, which allows them to offer the highest performing contacts possible.
Welded electrical contact tapes provide several key benefits in the operation of electronic equipment. Contact materials make sure that electricity flows correctly and does not cause short-circuits or overloads. Finally, these materials also maximize electrical equipment’s conductivity, thereby ensuring that they operate correctly. If you or your business needs electrical contact materials, consider visiting checon.com to view their wide selection of materials.
There are several materials and alloys that are used in creating contact materials in electrical contacts, which are both meant to help construct electrically conductive connective materials. Here are some different alloy materials used in constructing electrical contacts.
Refractory contacts are important in helping conduct electrical current through strategic placement in devices. The necessary conductivity and resistance help determine just what materials should be chosen for your product. The following are materials used to create refractory electrical contacts:
- Silver tungsten
- Silver Tungsten Carbide
- Silver Graphite
- Silver Tungsten Graphite Carbide
- Copper Tungsten
In successful electrical contacts manufacturing, buttons help your finished product be as effective as possible. The following are alloys used in the composition of creating both single buttons and multi-layer buttons:
- Silver Cadmium Oxide
- Silver Tin Oxide
- Silver Nickel
- Silver Alloy
- Copper and Copper Alloy
- Steel and Nickel Monel
- Braze Alloy
Rivets are created with the distinct purpose of extending that conductivity. The materials used and how they are constructed need to target the specific construction needs of the end-result product. The following are types of rivets that are manufactured to serve electrical contacts:
- Head and Shank
- Straight Side
- Chamfer Side
- Step Side
- Riveted Assemblies
Surface Features and Shapes
Varied shapes serve distinct purposes for the benefit of your products. The following alloy distinctions can help make a more intuitive design that enables a more efficiency and resiliency. Here are some characteristics that can be expected:
- Knurl and Score Lines
- For Backing Designations
- For Welding
- For Locating on the Substrate
- For Desired Performance
There are a wide range of metals that are used in making electrical contacts. In order to create a manufacturing plan best suited to your product, it doesn’t hurt to consult with an electrical contacts manufacturer to learn more.
NORTH ATTLEBORO, MA, SEPTEMBER 15, 2016: Checon Corporation is pleased to participate as a Platinum Sponsor of the upcoming 2016 HOLM IEEE Conference on Electrical Contacts, October 9-12th, in Clearwater, Florida, USA. This will be the twelfth year that Checon will co-sponsor this important technical forum covering the latest developments in the field of electrical contacts, contact materials and connectors. As a Platinum Level Sponsor and active participant in the HOLM Intensive Course that precedes the conference, Checon is committed to helping this event deliver on its promise of a dynamic program featuring technical research and practical application information critical to our customers.
For additional information on Checon and Checon PMC, visit the web site at www.checon.com.
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