Titanium boride

Titanium boride

Chembox new
ImageFile =
ImageSize =
OtherNames =
Section1 = Chembox Identifiers
CASNo = 12045-63-5
PubChem =

Section2 = Chembox Properties
Formula = TiB2
MolarMass = 69.5 g/mol
Appearance = metallic grey
Density =
MeltingPt =
BoilingPt =
Solubility =

Section3 = Chembox Structure
CrystalStruct = Hexagonal, Space group P6/mmm. Lattice parameters at room temperature: "a"=302.36 pm, "C"=322.04 pm
Coordination =
MolShape =

Section7 = Chembox Hazards
MainHazards =
FlashPt =
Autoignition =

Titanium Diboride (chemical formula TiB2) is an extremely hard ceramic compound (33 GPa) composed of titanium and boron that has very good wear resistance. It is resistant to oxidation in air at temperatures up to 1000C, and to hydrochloric and hydrofluoric acids, but reacts with alkalis, nitric acid and sulphuric acid. Unusually for a ceramic, it is a reasonable electrical conductor (about 105 Siemens per centimetre), so can be used as an anode material in aluminium smelting; this also means it can be shaped by electrical discharge machining.

It does not occur naturally in the earth; syntheses include heating a mixture of titanium dioxide and boron carbide to high temperature, followed by mechanical grinding, or reduction by the thermite reaction of a mixture of titanium dioxide, boron oxide and magnesium powders followed by dissolving magnesium oxide from the reaction mix [http://gtresearchnews.gatech.edu/newsrelease/TIB2.html] which produces a finer powder.

Many TiB2 applications are inhibited by economic factors, particularly the costs of densifying a high melting point material - the melting point is about 2970C, and, thanks to a layer of titanium dioxide that forms on the surface of the particles of a powder, it is very resistant to sintering, though an admixture of about 10% silicon nitride helps with this [http://www.patentgenius.com/patent/6420294.html] . Current use of this material appears to be limited to specialized applications in such areas as impact resistant armor, cutting tools, crucibles and wear resistant coatings. It is also used as an inoculant to refine the grain size when casting aluminium alloys.

Thin films of TiB2 have a wide range of potential industrial applications due to the wear and corrosion resistance properties that TiB2 can provide to a cheap and/or tough substrate. The electroplating of TiB2 layers possess two main advantages compared with plasma (PVD, CVD) methods: the growing rate of the layer is 200 times higher (up to 5 μm·s−1) and the inconveniences of covering complex shaped products are dramatically reduced.

Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • titanium boride — noun A very hard ceramic material, TiB, used as a refractory and in high temperature electrical applications …   Wiktionary

  • Boride — In chemistry a boride is a chemical compound between boron and a less electronegative element. This is a very large group of compounds that are generally high melting and are not ionic in nature. Some borides exhibit very useful physical… …   Wikipedia

  • Boron nitride — IUPAC name Boron nitride Identifiers …   Wikipedia

  • List of inorganic compounds — Tentative listing related to this page, inorganic compounds by element (presently under construction), as well as . This list is not necessarily complete or up to date ndash; if you see an article that should be here but isn t (or one that… …   Wikipedia

  • Electron beam physical vapor deposition — or EBPVD is a form of physical vapor deposition in which a target anode is bombarded with an electron beam given off by a charged tungsten filament under high vacuum. The electron beam causes atoms from the target to transform into the gaseous… …   Wikipedia

  • Metal matrix composite — A metal matrix composite (MMC) is composite material with at least two constituent parts, one being a metal. The other material may be a different metal or another material, such as a ceramic or organic compound. When at least three materials are …   Wikipedia

  • Chobham armour — A pre series American M1 Abrams, the first main battle tank type to be protected by Chobham armour …   Wikipedia

  • Functionally graded material — In materials science functionally graded material (FGM) may be characterized by the variation in composition and structure gradually over volume, resulting in corresponding changes in the properties of the material. The materials can be designed… …   Wikipedia

  • Борид титана(II) — Общие Систематическое наименование Борид титана(II) Химическая формула TiB2 Физические свойства Молярная масса 69,489 г/моль …   Википедия

  • Aluminium carbide — Aluminium carbide, chemical formula Al4C3, is a carbide of aluminium. It has the appearance of pale yellow to brown crystals with complex lattice structure. It is stable up to 1400 °C. Its density is 2.36 g/cm³. It is a methide: the carbon atoms… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”