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How about the conductivity of brass?

CLICK:257TIME:2018-11-27

What is the conductivity of brass?


Definition of conductivity of brass: The conductive current of an object can be called conductivity.


Brass is a copper-based alloy with zinc as its minor alloying element. It is named for its yellow color. Brass has beautiful color, good process and mechanical function, high conductivity and thermal conductivity, corrosion resistance in atmosphere, sea water and sea water, easy cutting and polishing, good weldability and low price. It is widely used in manufacturing conductive and heat conductive components, corrosion resistant structures, elastic components, daily hardware and decorative materials.


Complex brass binary copper-zinc alloy is called complex brass. With the addition of zinc content, its color changes from golden red to yellow, golden yellow and white. Zinc and copper can form six phases: alpha, beta, gamma, delta, epsilon and_. Alpha brass, (alpha+beta) brass and beta brass are commonly used in industry. The zinc content is generally not more than 50%. Among them, H62 and H68 brass have high plasticity and strength, good formability and are widely used. They can be used to manufacture various complex cold stamping and deep stamping parts, pipe fittings for waveguide tube and condenser, mechanical and electrical parts. H70 brass, also known as "gun copper", is used to manufacture shell and tube. Brass products with residual internal stress, temporarily stored in medium containing ammonia or sulfur dioxide, will occur intergranular or transgranular fracture. This phenomenon, known as stress corrosion cracking or seasonal cracking (quarterly cracking), can be eliminated by high temperature annealing. High zinc brass containing more than 20% zinc is prone to dezincification corrosion and can be inhibited by excessive arsenic, silicon, phosphorus and antimony.


In order to improve the function of complex brass, complex brass takes part in 1-5% tin, lead, aluminium, silicon, iron, manganese and nickel alloys, which are called "complex brass", and is crowned with the added elements, which are called tin brass, lead brass, aluminium brass, manganese brass and aluminium-manganese brass. Tin can inhibit dezincification corrosion and improve the corrosion resistance of brass. Tin brass is corrosion resistant in seawater and seawater, so it is called "naval brass". The solid solubility of lead brass is very small, and it is dispersed in the matrix as free particles, which can make chips fragmentation and smooth, thus improving the data machinability and wear resistance. Aluminum plays the role of solid solution strengthening, which makes the appearance of alumina film with maintenance function. Some aluminium brass can also have invisible memory effect and shock absorption ability after proper disposal. Silicon brass has high corrosion resistance, mechanical and casting functions, and can resist stress corrosion. Nickel brass has high strength, toughness and corrosion resistance, and can accept cold and thermoplastic processing.


Conductivity of copper?


Copper is named for its purple-white color. It is not necessarily pure copper, and sometimes participates in a large number of deoxidizing elements or other elements to improve the material and function, so it is also classified as copper alloy. Chinese copper processing materials can be divided into four categories according to their composition: ordinary copper (T1, T2, T3, T4), oxygen-free copper (TU1, TU2 and high purity, vacuum oxygen-free copper), deoxidized copper (TUP, TUMn), and special copper (arsenic-copper, tellurium-copper, silver-copper) with large amounts of alloying elements. Copper is only second to silver in conductivity and thermal conductivity, and is widely used in the manufacture of conductive and thermal conductive devices. Copper has good corrosion resistance in atmosphere, sea water, some non-oxidizing acids (hydrochloric acid, dilute sulfuric acid), alkali, salt solution and a variety of inorganic acids (acetic acid, citric acid) for chemical industry. In addition, copper has good weldability and can be processed into semi-finished products and finished products by cold and thermoplastic processing. In the 1970s, the output of copper exceeded the total output of other copper alloys.


Trace impurities in copper have a serious impact on the conductivity and thermal conductivity of copper. The effect of impurity elements on electrical conductivity is shown in Figure 2. Among them, titanium, phosphorus, iron and silicon significantly reduce the conductivity, while cadmium and zinc have little effect. Oxygen, sulphur, selenium, tellurium and other copper have little solid solubility, and can form brittle compounds with copper, which have little effect on conductivity, but can reduce the processing plasticity. When ordinary copper is heated in a restorative atmosphere containing hydrogen or carbon monoxide, hydrogen or carbon monoxide is liable to react with Cu2O at grain boundaries, resulting in high pressure steam or carbon dioxide gas, which can make copper crack. This phenomenon is often called copper "hydrogen disease". Oxygen is harmless to the weldability of copper. Bismuth or lead forms eutectic with copper at low melting point, which makes copper brittle, while brittle bismuth disperses at grain boundaries in a thin film shape, which makes copper brittle. Phosphorus can obviously reduce the conductivity of copper, but it can improve the activity of copper liquid and weldability. Excess lead, tellurium and sulfur can improve the machinability. The room temperature tensile strength of copper annealed sheet is 22-25 kg/mm 2, the elongation is 45-50%, and the Brinell hardness (HB) is 35-45.


What is the difference in conductivity between brass and copper?


Generally speaking, the conductor resistance is inversely proportional to the length of the conductor, but the conductive function of a conductor is secondary to the conductivity. Brass is copper-zinc alloy, and copper is pure copper. The less alloying elements in common copper, the better the conductive function.


1. The conductive current of an object can be called conductivity. All kinds of metals have different conductivity. Generally, silver has better conductivity, followed by copper and gold. Solid conduction refers to the short-range migration of electrons or ions in solids under the action of electric field, usually with a variety of charge carriers as the main conductor, such as: electronic conductors, mainly with electronic carriers; ionic conduction, mainly with ionic carriers; mixed conductors, which have both carrier electrons and ions. Besides, some electrical phenomena are not caused by carrier migration, but by solid polarization induced by electric field, such as dielectric phenomena and dielectric data.


2. Electrical conductivity of objects. Generally speaking, metals, semiconductors, electrolyte solutions or molten electrolytes and some non-metals can conduct electricity. The conductivity of a non-electrolytic object can be freed by the outer layer of its atom.

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