Boron Nitride cbn is an advanced ceramic known for its superior properties. BN chemistry has Azoto di boro bonds that give rise to different structures. Of the structures of BN one such prominent structure of interest is Cubic Boron Nitride cbn. Let us try to understand c-bn and its relative aspects.
Table of Contents
Nitruro di boro: una panoramica
Nitruro di boro esagonale (h-BN)
- Structure of Hexagonal Boron Nitride
- Properties of Hexagonal Boron Nitride
- Applicazioni del nitruro di boro esagonale
- What is cubic Boron Nitride?
- Structure of Cubic Boron Nitride
- Proprietà del nitruro di boro cubico
- Nitruro di boro cubico contro diamante
- Usi del nitruro di boro cubico
- Super abrasive wheels – or diamond c-BN wheel
Nitruro di boro: An Overview
Nitruro di boro is indicated by chemical formula “BN.” As earlier mentioned, Nitruro di boro exist in different forms. Generally, it is the location of Boron and Nitrogen in lattice that creates various Boron Nitride structures. Some of them are quiet famous such as amorphous, hexagonal, cubic and Wurtzite.
When it comes to functionality, Boron Nitride ceramic is highly machinable. Once machined they does not really require any heat sintering or treatment for stabilization. In addition, Nitruro di boro has higher heat capacity and is also a good electrical insulator.
For now, let’s try to understand derivatives of BN, Nitruro di boro esagonale (h-BN) and another Nitruro di boro cubico (c-BN)
Nitruro di boro esagonale (h-BN)
Structure of Hexagonal Boron Nitride
Nitruro di boro esagonale is a constituent in many industrial products such as cosmetics. HBN has a structure controlled by covalent bonds. However, the layers in HBN obey wander Waals forces. The plate like geometry of HBN is the reason why it is ideal for lubrication.
Nitruro di boro esagonale has elements of Boron and Nitrogen fixed to its lattice. The arrangement has three nitrogen atoms attached to a Boron Atom. The similarity in the honeycomb structure is the reason for its analogy with carbon. In addition to, properties of mechanical, chemical strength and electrical insulation are due to the planar triangular bonds
Properties of Hexagonal Boron Nitride
Nitruro di boro esagonale is popularly manufactured through Boric Oxide nitridation at elevated temperatures. Since its stability is closer to graphene, Nitruro di boro esagonale is often acclaimed as the most advanced technical ceramic. Some superior properties of Nitruro di boro esagonale sono la sua conduttività termica e il basso coefficiente di attrito.
Applicazioni del nitruro di boro esagonale
- HBN is used on nanoelectronics devices as a substitute to graphene substrate
- Nitruro di boro esagonale in its thin form is used as coatings that resists corrosion
- HBN is often used in the manufacture of sensor materials. It is also used in electron tunneling due to its low value of dielectric constant.
Nitruro di boro cubico
What is cubic Boron Nitride?
c-BN è un derivato di Nitruro di boro esagonale (h-BN) produced under high temperature and pressure.
La più grande specialità di c-BN è che detiene il posto di secondo materiale più duro al mondo. La resistenza meccanica di Nitruro di boro cubico è popolare ed è alla pari con il diamante. È uno dei polimorfi del boro più popolari. Nitruro.
Structure of Nitruro di boro cubico
The basic structure of Nitruro di boro cubico is crystalline. It has density around 3.5 g/cm3 and appears in pale yellow or transparent complexion. C-BN follows alternate arrangement of Boron and Nitrogen atoms. Here, the Azoto di boro atoms follow covalent bonding which is the basic reason of its hardness and stability.
Cubic Boron Nitride Formula is given as c-BN. There are two popular types of c-Bn available today in the market. One is dense nitruro di boro cubico and the other polycrystalline cubic Boron Nitride.
Cubic Boron Nitride Properties
C-BN is a brilliant semiconductor whose bandgaps are susceptible to changes in applied pressure. These changes in bandgap helps them excel as electric insulators. Nitruro di boro cubico are generally inert and possesses low dielectric constant value. Their thermal conductivity is around 1300 KW/MK.
When it comes to reactivity, c-BN remains non-respondent even to ferrous materials. The optical range dealt by nitruro di boro cubico varies from Ultra violet to the visible spectrum.
Nitruro di boro cubico contro diamante
Sebbene non sia più duro del diamante, nitruro di boro cubico ha un posto speciale se paragonato al diamante. Cubic boron Nitride hardness is 4500 Kg/mm2 whereas diamond has hardness around 600 Kg/mm2.The value of modulus both young’s and bulk are also in similar range of 800 – 1000 and 370 – 450.
Furthermore, when it comes to structure, like diamond, c-BN has its two base atoms that are different. The similarity of both diamond and c-BN is generally attributed to the lookalike structure they possess.
Usi del nitruro di boro cubico
materiale per utensili da taglio cbn
Nitruro di boro cubico exhibits both young’s and Bulk modulus greater than Boron Carbide and Silicon Carbide. This very reason strongly contributes to the hardness of cubic Boron Nitride. The hardness makes them suitable as abrasives and help them function as materiale per utensili da taglio cbn. Generally Dense c-Bn is used for cutting application and porous type for grinding requirements.
The inert nature of Cubic Boron Nitride also helps them function as cutting and machining material. Unlike diamond it doesn’t react to iron. However, conventional c-Bn requires manipulation for utilising it in cutting application. This is generally done during the conversion of h-Bn to c-Bn while sintering.
cbn as electrical insulators
Apart from hardness Nitruro di boro cubico also excels in electrical insulators. This is attributed to their wide bandgap.
cbn in semiconductor applications
By coating aluminium and Group 8 metals, C-BN functionality of becoming a sink is popular in electronic industry. C-BN is used as heat sink in lasers, microelectronic devices and LEDs.
Nitruro di boro cubico also adds value during semiconductor synthesis to obtain p and N type by proper doping. The common materials used for doping are Silicon or Beryllium. These semiconductors work at high temperature and are used in UV sensors.
mole abrasive c-BN
L'invenzione di mole abrasive c-BN merited precision manufacturing due to the increased efficiency. wheels made up of c-BN contributed to industries such as aerospace, machines, tool production and automobile. mole abrasive c-BN also offer high hardness and good performance on comparison with SiC and Alumina. They ensure structural integrity at higher temperature and undergo no degradation.
The wheels of c-BN can withstand high temperature and deals with the amount of heat generated during the process. The resistance to wear and tear is also economically beneficial while considering c-BN grinding wheels. c-BN grinding wheels offer excellent surface finish and keeps away the work piece wastage. It also ensures lesser cycle time as the tasks are done quickly and precisely.
Super abrasive wheels – or diamond c-BN wheel
The super abrasive wheels are the ones differ from conventional wheel of Sic and Alumina. They are made from combining c-Bn and diamond. The super abrasive wheel offers better thermal conductivity limiting the rise in temperature of the workpiece. The mola diamantata c-Bn offrono inoltre un'elevata accuratezza e precisione di taglio che contribuiscono a una maggiore durata.
Conclusione
Nitruro di boro cubico Sono desiderabili nella scienza moderna e nella produzione di materiali. Sono competitivi rispetto a materiali come il diamante. Eccellono in proprietà come durezza, resistenza e isolamento elettrico. L'ampio band gap, la natura inerte, la bassa costante dielettrica e le proprietà ottiche sono altri fattori di merito.