Characteristics of Electric Conductors

Electrical Conductors

Electrical conductors are materials that allow electric current to flow through them with minimal resistance. In other words, they have high electrical conductivity. Conductors are usually metals, such as copper, silver, gold, and aluminum, but they can also include some non-metals, such as graphite. The electrons in conductive materials are able to move freely, allowing electric current to pass through the material with ease. This property makes conductors useful in many electrical applications, such as wiring, circuits, and electronic devices.

The main characteristics of electric conductors are:

High electrical conductivity: Conductors have a high ability to conduct electric current through them with minimal resistance.
Low resistivity: Conductors have low resistivity, which is a measure of how much a material resists the flow of electric current.
High melting point: Conductors have high melting points, which means they can withstand high temperatures without melting or degrading.
Ductility: Conductors are often ductile, which means they can be easily drawn into wires or other shapes without breaking.
Malleability: Conductors are often malleable, which means they can be easily shaped or molded without breaking.
High density: Conductors are often dense materials, which means they have a high mass per unit volume.
High thermal conductivity: Many conductors also have high thermal conductivity, which means they can transfer heat efficiently.

Here is a table of 10 most common conductors with their main parameters:

Conductor	Electrical Conductivity (S/m)	*Thermal Conductivity (W/mK)**	Melting Point (°C)	Density (g/cm³)
Silver (Ag)	62.6 × 10^6	429	961.8	10.49
Copper (Cu)	58.0 × 10^6	401	1,085	8.96
Gold (Au)	45.5 × 10^6	320	1,064	19.30
Aluminum (Al)	37.7 × 10^6	237	660.3	2.70
Tungsten (W)	18.8 × 10^6	173	3,422	19.25
Nickel (Ni)	14.4 × 10^6	91.7	1,455	8.91
Iron (Fe)	10.0 × 10^6	80.4	1,538	7.87
Zinc (Zn)	16.6 × 10^6	116	419.5	7.13
Brass (CuZn)	15.6 × 10^6	109	900-940	8.4-8.7
Bronze (CuSn)	7.8 × 10^6	61.2	870-1,040	7.5-8.8

Materials with the highest electrical conductivity

Here are seven materials with the highest electrical conductivity:

Silver – Silver has the highest electrical conductivity of all metals and is widely used in electrical and electronic applications due to its low resistance and high thermal conductivity.
Copper – Copper is the second-most conductive metal after silver and is commonly used in electrical wiring and electronic components.
Gold – Gold is a good conductor of electricity and is commonly used in electronic connectors, switches, and other components due to its corrosion resistance and low reactivity.
Aluminum – Aluminum is a lightweight metal with good electrical conductivity and is used in a variety of electrical applications, such as power transmission and distribution.
Tungsten – Tungsten has a high melting point and is a good conductor of electricity, making it useful in high-temperature electrical applications such as incandescent light bulbs and vacuum tubes.
Platinum – Platinum is a dense, corrosion-resistant metal with high electrical conductivity and is used in a variety of electrical and electronic applications.
Brass – Brass is an alloy of copper and zinc that has good electrical conductivity and is commonly used in electrical connectors, switches, and other components.

Electrolytic-tough pitch (ETP) copper

Electrolytic tough pitch copper, UNS C11000, is pure copper (with a maximum of 0.0355% impurities) refined by the electrolytic refining process. It is the most widely used grade of copper all over the world. ETP has a minimum conductivity rating of 100% IACS and is required to be 99.9% pure. It has 0.02% to 0.04% oxygen content (typical). Electrical wiring is the most important market for the copper industry. This includes structural power wiring, power distribution cable, appliance wire, communications cable, automotive wire and cable, and magnet wire. Roughly half of all copper mined is used for electrical wire and cable conductors. Pure copper has the best electrical and thermal conductivity of any commercial metal. The conductivity of copper is 97% that of silver. Due to its much lower cost and greater abundance, copper has traditionally been the standard material for electricity transmission applications.

According to the Copper Development Association:

“The term ‘tough pitch’ originates from the time when molten copper, after refining, was cast into ingot moulds. During refining, the copper was oxidized to remove impurities and then reduced by hydrogen to give the correct oxygen level. To monitor this process, a small sample was taken, and the solidification surface was observed. If the surface sunk, there was too much oxygen; if it was raised, there was too much hydrogen. If it was level (correct pitch), the oxygen was correct, and the properties good; in other words, ’ tough,’ hence tough pitch. “

Source: https://copperalliance.org

Electrical Conductivity and Materials

Electrical conductivity can be defined as how much voltage is required to get an amount of electric current to flow. This is largely determined by the number of electrons in the outermost shell; these electrons determine the ease with which mobile electrons are generated. Another factor is the number of atoms per unit volume, which determines the number of electrons that will readily move in response to an electric field. Materials that have high electrical conductivity are typically metals and alloys, as well as some types of salts and solutions. This is because these materials have a large number of free electrons that are not bound to individual atoms and are able to move freely through the material.

Metals such as copper, aluminum, silver, and gold are well-known for their high electrical conductivity and are commonly used in electrical and electronic applications. Other metals and alloys with high electrical conductivity include tungsten, platinum, and brass.

Some types of salts and solutions also have high electrical conductivity due to the presence of free ions that can carry an electric charge. For example, solutions of sodium chloride (table salt) or other salts can conduct electricity well, as can some types of acids and bases.

Classification of Materials according to Electrical Conductivity

Materials can be classified into different categories based on their electrical conductivity. Here are some common categories:

Conductors: Materials with high electrical conductivity, such as metals and some types of solutions, are known as conductors. They are able to carry an electric current with minimal resistance and are commonly used in electrical and electronic applications.
Insulators: Materials with low electrical conductivity, such as plastics, rubber, and glass, are known as insulators. They are not able to carry an electric current easily and are commonly used to isolate and protect electrical components.
Semiconductors: Materials that have intermediate levels of electrical conductivity, such as silicon and germanium, are known as semiconductors. They can be used to control and manipulate the flow of electric charge and are used extensively in electronics and computer applications.
Superconductors: Materials that have zero electrical resistance at very low temperatures are known as superconductors. They are able to carry electric current without any loss of energy and are used in specialized applications such as MRI machines and particle accelerators.
Ionic conductors: Materials that conduct electricity through the movement of ions rather than electrons, such as some types of salts and electrolytes, are known as ionic conductors. They are commonly used in batteries, fuel cells, and other electrochemical devices.

Generally, most metals have high conductivity (which is another way of saying metals tend to be conductors) because the electrons in their outermost shell can move easily. Non-metals tend to have low conductivity.

Electrical Conductors