Electrocorundum

Electrocorundum (Al₂O₃) — is a fireproof and chemically resistant material based on aluminum oxide.

Products made from electrocorundum have physical and mechanical stability, excellent electrical and chemical properties.

Advantages of corundum ceramics:

high strength and wear resistance – corundum ceramics withstands high friction loads;
excellent thermal insulation – a body made of this material provides thermal insulation at temperatures of 1800-1850 °C;
good translucency – transmits rays well without visible distortion;
this ceramics does not melt when heated in an alkaline environment and when melting metals: magnesium, cobalt, nickel, etc.;
the material does not collapse at pressures up to 30 MPa and at temperatures up to 370 MPa, retains its shape when heated in hydrochloric and sulfuric acid to 100 °C.

Silicon carbide

Silicon carbide (SiC) is a synthetic substitute for the rare mineral moissanite, which is found in nature only in deposits of corundum and kimberlite, and even more rarely in meteorites that fell to Earth from space.

Silicon carbide-based ceramics, due to its high physical and mechanical characteristics, is a widely used material in various fields of industry and mechanical engineering.

The most attractive properties of silicon carbide are considered to be high strength, hardness, abrasion resistance, low temperature coefficient of linear expansion, and the ability to withstand significant power and thermal loads in aggressive environments.

Advantages of silicon carbide ceramics:

Silicon carbide is used in the production of semiconductor products because it has high thermal conductivity and electric current density.
Silicon carbide (SiC) has a hardness second only to diamond and boron carbide and is highly resistant to wear (mechanical seals, etc.).
Its hardness makes silicon carbide an excellent abrasive, which is used for grinding, sandblasting, and honing.
In addition, silicon carbide has a high Young’s modulus and a low coefficient of thermal expansion, so it is used for components (optical parts, substrates, etc.) that require high precision.
Because it is a dense sintered body, it can be polished to a mirror finish. It has high temperature resistance over 1400°C and thermal shock resistance with excellent chemical stability.
High-purity silicon carbide is used in semiconductor production.
Silicon carbide (SiC) products have higher mechanical strength compared to synthetic aluminum and silicon nitride materials, especially in terms of high temperature resistance, wear resistance and corrosion resistance.

Zirconium oxide

The compound zirconium oxide (ZrO₂) was discovered by Hussak in 1892. It exists in a natural ore – zircon sand or baddeleyite.

Zirconium oxide ceramics are characterized by high strength, high resistance, high hardness, and excellent chemical, corrosion and abrasion resistance.

Advantages of zirconium oxide ceramics:

Zirconium oxide ZrO₂ has high hardness and bending strength.
Among the three types of ceramics, including aluminum oxide Al₂O₃, silicon carbide SiC and zirconium oxide ZrO2, the latter has the highest strength, exceeding 8 MPa • m1/2.
Zirconium oxide ZrO₂ has high wear resistance and low friction coefficient. Its resistance to abrasive wear is 15 times higher than that of corundum ceramics.
after abrasive treatment, its surface becomes even smoother and can reach ▽ 9.
It has good thermal insulation and strong corrosion resistance, and does not conduct static electricity.
resistant to high temperatures and has excellent thermal insulation properties.
It is self-lubricating and can solve the problem of contamination caused by lubricant and the inconvenience of adding it.

Boron nitride

Boron nitride is a refractory compound of boron with nitrogen, which has high thermal insulation, insulating and semiconductor properties, and a low temperature coefficient of linear expansion.

Unique properties of boron nitride (BN) ceramics:

high heat resistance: the melting point of the substance is 2973 °C. According to this indicator, boron nitride is on a par with metals such as hafnium, osmium and molybdenum.
One of the highest thermal shock resistance ratings in its class: withstands extreme temperature cycles from 1500°C (with rapid air cooling) to room temperature and back for dozens of times without destruction, and 2800℃ in inert gas without softening.
high thermal conductivity: hot-pressed products have the thermal conductivity of pure iron. At 1700–2000 W/mK, the thermal conductivity of BN is comparable to that of graphene.
At temperatures above 530 °C this material has the best thermal conductivity among ceramic materials.
low coefficient of thermal expansion: second only to quartz glass.
Excellent electrical properties: good high-temperature insulation, the resistivity at room temperature is more than 10^14Ω-cm, and at 2000°C it can reach 10^3Ω-cm, which is the best high-temperature insulation material in ceramics.
From a chemical point of view, boron nitride is inert. The substance does not react with reagents and molten metals, including titanium, copper, aluminum and others.
resistant to acidic and alkaline environments.
Low friction coefficient: U is 0.16, it does not increase at high temperature, and it is more resistant to high temperature than molybdenum disulfide and graphite.
good machinability: hardness allowing BN parts to be processed with high precision using general machining methods.

Boron carbide

Boron carbide is a binary compound of boron with carbon, having the formula B4C. It was first obtained in 1893 by A. Moissan by reducing boron oxide B2O3 with carbon at 2000 °C.

Boron carbide is a lightweight, refractory, highly hard, chemically inert material that also has semiconductor properties.

Thanks to this complex of unique properties, boron carbide is in demand in high-tech industries: nuclear power (neutron absorber), mechanical engineering (component of wear-resistant surfacing mixtures, refractory materials; abrasive-resistant nozzles and cutters; abrasive material, etc.), electronics (semiconductor p- type), defense industries (armor protection elements, body armor).

Advantages of boron carbide ceramics:

boron carbide is known for its exceptional hardness,
high abrasion resistance and chemical stability,
high strength, wear resistance and one of the best shock absorption abilities in its class,
boron carbide has unique characteristics of thermal stability and corrosion resistance, which makes it indispensable in extreme conditions,
has excellent chemical stability and electrical conductivity, making it ideal for use in electronics and optoelectronics.

CERAMIC MATERIALS

Electrocorundum

Silicon carbide

Zirconium oxide

Boron nitride

Boron carbide