It is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds. Carbon is one of the few elements known since antiquity. Carbon is the 15th most abundant element in the Earth’s crust, and the fourth most abundant element in the universe by mass after hydrogen, helium, and oxygen.
|Element category||Non Metal|
|Phase at STP||Solid|
|Ultimate Tensile Strength||15 MPa (graphite); 3500 MPa (carbon fiber)|
|Young’s Modulus of Elasticity||4.1 GPa (graphite); 228 GPa (carbon fiber)|
|Mohs Scale||0.8 (graphite)|
|Melting Point||4099 °C|
|Boiling Point||4527 °C|
|Thermal Conductivity||129 W/mK|
|Thermal Expansion Coefficient||0.8 µm/mK|
|Specific Heat||0.71 J/g K|
|Heat of Fusion||— kJ/mol|
|Heat of Vaporization||355.8 kJ/mol|
|Electrical resistivity [nanoOhm meter]||7837|
|Magnetic Susceptibility||−5.9e-6 cm^3/mol|
Applications of Carbon
The major economic use of carbon other than food and wood is in the form of hydrocarbons, most notably the fossil fuel methane gas and crude oil (petroleum). Graphite and diamonds are two important allotropes of carbon that have wide applications. The uses of carbon and its compounds are extremely varied. It can form alloys with iron, of which the most common is carbon steel. Carbon is a non-metallic element, which is an important alloying element in all ferrous metal based materials. Carbon is always present in metallic alloys, i.e. in all grades of stainless steel and heat resistant alloys. Carbon is a very strong austenitizer and increases the strength of steel. In fact, it is the principal hardening element and is essential to the formation of cementite, Fe3C, pearlite, spheroidite, and iron-carbon martensite. Adding a small amount of non-metallic carbon to iron trades its great ductility for the greater strength. Graphite is combined with clays to form the ‘lead’ used in pencils used for writing and drawing. It is also used as a lubricant and a pigment, as a molding material in glass manufacture, in electrodes for dry batteries and in electroplating and electroforming, in brushes for electric motors and as a neutron moderator in nuclear reactors. Charcoal has been used since earliest times for a large range of purposes including art and medicine, but by far its most important use has been as a metallurgical fuel. Carbon fibers are used where low weight, high stiffness, high conductivity, or where the look of the carbon fiber weave desired.
Production and Price of Carbon
Raw materials prices change daily. They are primarily driven by supply, demand and energy prices. In 2019, prices of pure Carbon were at around 24 $/kg.
Graphite, diamond and other carbon forms are directly obtained from mines. Synthetic diamonds can be produced when pure carbon is subjected to extremely high temperatures and pressures. Today, about 1/3rd of all diamonds are synthetically produced. Commercially viable natural deposits of graphite occur in many parts of the world, but the most important sources economically are in China, India, Brazil and North Korea. According to the USGS, world production of natural graphite was 1.1 million tonnes in 2010, to which China contributed 800,000 t, India 130,000 t, Brazil 76,000 t, North Korea 30,000 t and Canada 25,000 t.
Mechanical Properties of Carbon
Strength of Carbon
In mechanics of materials, the strength of a material is its ability to withstand an applied load without failure or plastic deformation. Strength of materials basically considers the relationship between the external loads applied to a material and the resulting deformation or change in material dimensions. In designing structures and machines, it is important to consider these factors, in order that the material selected will have adequate strength to resist applied loads or forces and retain its original shape. Strength of a material is its ability to withstand this applied load without failure or plastic deformation.
For tensile stress, the capacity of a material or structure to withstand loads tending to elongate is known as ultimate tensile strength (UTS). Yield strength or yield stress is the material property defined as the stress at which a material begins to deform plastically whereas yield point is the point where nonlinear (elastic + plastic) deformation begins.
See also: Strength of Materials
Ultimate Tensile Strength of Carbon
Ultimate tensile strength of Carbon is 15 MPa (graphite); 3500 MPa (carbon fiber).
Yield Strength of Carbon
Yield strength of Carbon is N/A.
Modulus of Elasticity of Carbon
The Young’s modulus of elasticity of Carbon is 4.1 GPa (graphite) – 228 GPa (carbon fiber).
Hardness of Carbon
In materials science, hardness is the ability to withstand surface indentation (localized plastic deformation) and scratching. Brinell hardness test is one of indentation hardness tests, that has been developed for hardness testing. In Brinell tests, a hard, spherical indenter is forced under a specific load into the surface of the metal to be tested.
Brinell hardness of Carbon is approximately N/A.
The Vickers hardness test method was developed by Robert L. Smith and George E. Sandland at Vickers Ltd as an alternative to the Brinell method to measure the hardness of materials. The Vickers hardness test method can be also used as a microhardness test method, which is mostly used for small parts, thin sections, or case depth work.
Vickers hardness of Carbon is approximately N/A.
Scratch hardness is the measure of how resistant a sample is to permanent plastic deformation due to friction from a sharp object. The most common scale for this qualitative test is Mohs scale, which is used in mineralogy. The Mohs scale of mineral hardness is based on the ability of one natural sample of mineral to scratch another mineral visibly.
Carbon is has a hardness of approximately 0.8 (graphite).
See also: Hardness of Materials
Carbon – Crystal Structure
A possible crystal structure of Carbon is hexagonal structure.
In metals, and in many other solids, the atoms are arranged in regular arrays called crystals. A crystal lattice is a repeating pattern of mathematical points that extends throughout space. The forces of chemical bonding causes this repetition. It is this repeated pattern which control properties like strength, ductility, density, conductivity (property of conducting or transmitting heat, electricity, etc.), and shape. There are 14 general types of such patterns known as Bravais lattices.
See also: Crystal Structure of Materials
Thermal Properties of Carbon
Carbon – Melting Point and Boiling Point
Melting point of Carbon is 4099°C.
Boiling point of Carbon is 4527°C.
Note that, these points are associated with the standard atmospheric pressure.
Carbon – Thermal Conductivity
Thermal conductivity of Carbon is 129 W/(m·K).
The heat transfer characteristics of a solid material are measured by a property called the thermal conductivity, k (or λ), measured in W/m.K. It is a measure of a substance’s ability to transfer heat through a material by conduction. Note that Fourier’s law applies for all matter, regardless of its state (solid, liquid, or gas), therefore, it is also defined for liquids and gases.
Coefficient of Thermal Expansion of Carbon
Linear thermal expansion coefficient of Carbon is 0.8 µm/(m·K)
Thermal expansion is generally the tendency of matter to change its dimensions in response to a change in temperature. It is usually expressed as a fractional change in length or volume per unit temperature change.
Carbon – Specific Heat, Latent Heat of Fusion, Latent Heat of Vaporization
Specific heat of Carbon is 0.71 J/g K.
Heat capacity is an extensive property of matter, meaning it is proportional to the size of the system. Heat capacity C has the unit of energy per degree or energy per kelvin. When expressing the same phenomenon as an intensive property, the heat capacity is divided by the amount of substance, mass, or volume, thus the quantity is independent of the size or extent of the sample.
Latent Heat of Fusion of Carbon is — kJ/mol.
Latent Heat of Vaporization of Carbon is 355.8 kJ/mol.
Latent heat is the amount of heat added to or removed from a substance to produce a change in phase. This energy breaks down the intermolecular attractive forces, and also must provide the energy necessary to expand the gas (the pΔV work). When latent heat is added, no temperature change occurs. The enthalpy of vaporization is a function of the pressure at which that transformation takes place.
Carbon – Electrical Resistivity – Magnetic Susceptibility
Electrical property refers to the response of a material to an applied electric field. One of the principal characteristics of materials is their ability (or lack of ability) to conduct electrical current. Indeed, materials are classified by this property, that is, they are divided into conductors, semiconductors, and nonconductors.
See also: Electrical Properties
Magnetic property refers to the response of a material to an applied magnetic field. The macroscopic magnetic properties of a material are a consequence of interactions between an external magnetic field and the magnetic dipole moments of the constituent atoms. Different materials react to the application of magnetic field differently.
See also: Magnetic Properties
Electrical Resistivity of Carbon
Electrical resistivity of Carbon is 7837 nΩ⋅m.
Electrical conductivity and its converse, electrical resistivity, is a fundamental property of a material that quantifies how Carbon conducts the flow of electric current. Electrical conductivity or specific conductance is the reciprocal of electrical resistivity.
Magnetic Susceptibility of Carbon
Magnetic susceptibility of Carbon is −5.9e-6 cm^3/mol.
In electromagnetism, magnetic susceptibility is the measure of the magnetization of a substance. Magnetic susceptibility is a dimensionless proportionality factor that indicates the degree of magnetization of Carbon in response to an applied magnetic field.
Application and prices of other elements