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Views: 325 Author: Site Editor Publish Time: 2022-02-16 Origin: Site
We know that small electrical contacts can control current in electrical equipments, and they are also one of important electronic circuit components. Usually it is mainly used in circuit breakers, relays, connectors and switches. When it works, the contact with metal parts will open and close the circuit through the electrical device. Therefore, when metal stamping parts are connected, the circuit will close and carry current to make the device working. On the contrary, when an insulating air gap separates the small contacts component, the circuit will open and is interrupted. This is the working principle of contacts. Then what advantages to use gold-plated electrical contacts? Now let us to know the relative knowledge of the contacts.
Why the contacts need to be gold plated?
Generally speaking, many standard and customized electrical contacts are made of nickel, copper, cadmium and various other alloys, since they all belong to conductive metals. But there are some disadvantages for these conductive metals, and they will degrade due to oxidation, corrosion, erosion, and heat after using for a long time. Then how to avoid it? The contacts manufacturers think a good way that they use a thin layer of gold plating with a nickel primer to protect the contacts and improve their performance. Maybe some people will wonder why use gold plating? It will increase the electrical contacts cost. That is because gold has various physical and chemical properties, which make it be an ideal electronic application. Here are some advantages as follows that make it a reliable long-term return on investment.
What advantages to use gold-plated contacts?
1. The gold-plated layer has strong hardness and is resistant to plugging and unplugging. Of course, the price is a little expensive comparing with other common electrical contacts.
2. The appearance of the gold-plated layer is golden yellow and has high chemical stability. It is only soluble in aqua regia and insoluble in other acids. We know that the atomic valences of gold are monovalent and trivalent. The standard potential of univalent gold is 0 Au T/A, and it is +1.68V. The standard potential of trivalent gold is 9 Au T/A, which is +1.50V. For steel, copper, silver and their alloy substrates, the gold coating is a cathodic coating, and the pores of the coating can affect its protective performance.
3. The gold-plated coating has good ductility, and it is easy polishing, high temperature resistance, and good discoloration resistance. Gold plating on the silver layer can prevent the discoloration of silver. The gold alloy plating layer can present a variety of tones. So, it is often used as a decorative plating layer, such as plating jewelry, watch parts, artwork etc.
4. Gold has low contact resistance, good electrical conductivity, easy to weld and strong corrosion resistance. Hard gold also has a certain degree of wear resistance, so it is used in many fields such as precision instruments, printed circuit boards, integrated circuits, tube cases, electric contacts and other aspects. All in all, it has a wide range of applications.
