Titan, You, Atomic number 22

General

Titanium is a chemical element with the chemical symbol Ti and atomic number 22. It belongs to the transition metals in the periodic table in the 4. Subgroup (group 4) or titanium group. The metal is white, shiny metallic, slightly, fixed, flexible, corrosion- and temperature-resistant. It is therefore particularly suitable for applications, which require a high corrosion resistance, Strength and low weight arrives. Due to the complicated production process, titanium is ten times as expensive as conventional steel.

Titanium was 1791 discovered in England by the clergyman and amateur chemist William Gregor in titanium iron. 1795 discovered it, the German chemist Heinrich Klaproth in rutile ore and also gave the element - based on the Greek race of gods of the Titans - its present name.

However, it was only in the year 1831 Justus von Liebig, to gain from the ore, the metallic titanium. Reines Titanmetall (99,9 %) presented 1910 erstmals Matthew A. Hunter her, by on in a steel bomb titanium tetrachloride mitNatrium 700 to 800 Heated ° C.

Only in the 1940s succeeded William Justin Kroll with the Kroll process by introducing the large-scale reduction of titanium tetrachloride with magnesium to tap the titanium for commercial applications.

Occurrence

Titanium is used in the earth's crust only in compounds with oxygen as the oxide. It is not rare, it does however with a content of 0,565 % an 9. Place of the element abundance in the continental crust. Mostly, however, it is present only in low concentration.

Important minerals are:

  • Ilmenite (Ilmenite), FeTiO3
  • Leukoxen, an iron-poor ilmenite
  • Perovskite, CaTiO3
  • Rutile, TiO2
  • Titanit (Sphen), How[SiO4]The
  • Titanate wie Bariumtitanat, (BaTiO3)
  • Companion in iron ore.

The main deposits are in Australia, Scandinavia, North America, the Urals and Malaysia. In 2010 deposits were discovered in Paraguay, To date, however, their exploitation is planned only.

Meteorites can contain titanium. In the sun and in stars of spectral type M also titanium was detected. On the Earth's moon deposits are also available. Rock samples from the moon mission Apollo 17 containing up to 12,1 % TiO2. There are considerations for asteroid mining.

Even in coal ash, Plants and in the human body is contained.

Titanium production in thousand tons
Rank Land 2003 2004 2005
1 Australien Australia 1 300 2 110 2 230
2 Südafrika South Africa 1 070 1 130 1 130
3 Kanada Canada 810 870 870
4 China China 400 840 820
5 Norwegen Norway 380 370 420

Extraction

Pure titanium is in the ground almost before. Titanium is extracted from ilmenite or rutile. The manufacturing process used here is very expensive, what is the high price of titanium is reflected. Sun in cost 2008 an average of one ton of titanium sponge 12.000 Euro.

The manufacturing process is almost unchanged since the discovery of the Kroll process. Most of ilmenite or rutile starting, titanium dioxide is enriched in the heat with chlorine and carbon to titanium(IV)-chloride and carbon monoxide implemented. Subsequently, the reduction can be done to Titan by liquid magnesium. To produce editable alloys of titanium sponge obtained thereby must be melted in a vacuum arc furnace.

Largest producer of titanium and titanium alloys is the VSMPO-AVISMA or with headquarters in Verkhnaya Salda. Im Ural Yekaterinburg, which since 12. September 2006 is indirectly through the holding in Russian Rosoboronexport state-owned.

Pure titanium is recovered by the Van Arkel-de Boer process.

Properties

Titanium forms from the air an extremely resistant protective oxide layer, it resists corrosion in many media makes. Noteworthy is the high strength at a relatively low density. Above a temperature of 400 ° C, the strength properties but quickly go back. High-purity titanium is ductile. At higher temperatures it is embrittled by oxygen uptake, Nitrogen and hydrogen very quickly. Also of note is the high reactivity of titanium with a lot of media at elevated temperatures and elevated pressure, if the passive layer is not up to the chemical attack. Here, the reaction rate can increase up to the explosion. In pure oxygen at 25 ° C and 25 titanium bar burns from a fresh cut edge, starting all the way to titanium dioxide. Despite passivation layer reacts at temperatures above 880 ° C with oxygen, at temperatures from 550 °C mit Chlor. Titanium reacts ("Burns") with pure nitrogen, which must be strictly observed, for example, during machining processes due to heat.

To dilute sulfuric acid, Salzsäure, chloride-containing solutions, cold nitric acid and most organic acids and bases such as sodium hydroxide, titanium is resistant. In contrast, concentrated sulfuric acid it dissolves slowly in, with the formation of the purple titanium sulfate. Because of the danger of explosion in applications are in chlorine gas, the operating conditions must be strictly adhered.

The mechanical properties and the corrosive behavior can be described by mostly minor alloying additions of aluminum, Vanadium, Mangan, Molybdenum, Palladium, copper, Greatly improve zirconium and tin.

Below a temperature of 0,4 K is titanium superconducting.

Below 880 ° C titanium in a hexagonal closest packing ago. Above 880 ° C forms a body-centered cubic lattice structure of.

Titanium alloys

Titanium alloys are frequently according to the U.S. standard ASTM Grade 1 to 35 characterized. Grade 1 to 4 called pure titanium of different degrees of purity.

Pure titanium is the material number 3.7034; the most economically important (for turbocharger blades) Material used Ti-6Al-4V (6 % Aluminium, 4 % Vanadium, ASTM:Grade 5) is the number 3.7165 (industrial application) and 3.7164 (Aerospace applications).

Other important titanium alloys, which are used primarily in the aerospace industry:

Designation chem. Composition Elastizitätsmodul in GPa Density in g·cm−3
Ti6246 Ti-6Al-2Sn-4Zr-6Mo 125,4 4,51
Ti6242 Ti-6Al-2Sn-4Zr-2Mo 4,50

Nitinol (Nickel-Titan) is a so-called shape memory alloy.

Use

Titanium is used primarily as micro-alloying element for steel. It makes steel at concentrations of 0.01-0.1 percent by weight of a high strength, Strength undDuktilität. In stainless steels, titanium prevents intergranular corrosion.

Titanium-based alloys with approximately. 45 € / kg significantly more expensive than superalloys. They are therefore used only for the highest requirements:

Applications in seawater and chloride-containing media

  • Ship propeller parts such as shafts, and tension for maritime applications
  • Fixtures in seawater desalination
  • Components for the evaporation of potassium chloride solutions
  • Anodes of HVDC Seekabelübertragungen
  • Apparatus in plants of chlorine chemistry

Outdoor- and sporting goods

  • in quality cycles in combination with aluminum and vanadium as the frame material
  • (Diver-)Messer mit Titan- or titanium alloy blades, as cutlery
  • as tent pegs (High strength despite low weight)
  • with golf clubs as club head
  • Tennis rackets under
  • when curling as extremely stable during curling rod handle
  • as particularly light ice screw while rock climbing
  • as lacrosse shaft for greater strength with less weight
  • as a solid bite leader when fishing for predators with sharp teeth

Use in the form of compounds

  • Production of relatively soft artificial gemstones
  • titanium-doped sapphire single crystals are used as the active medium in the titanium-sapphire laser for ultrashort pulses in the femtosecond range
  • than titanium tetrachloride to produce glass mirrors and artificial fog
  • Formation of intermetallic phases (Or3You) in high-temperature nickel alloys
  • superconductive niobium-titanium alloys (of. B. as superconducting cable in the electromagnet of HERA at DESY)
  • in pyrotechnics
  • about 90 % the Titanerzförderung is mainly by the chloride- titanium dioxide and processed to a lesser extent by the sulphate process.
  • as for titanium nitrite coating of indexable inserts and cutters in the manufacturing technology

Compounds of titanium with boron, Carbon or nitrogen are used as hard materials. For the production of cermet, Composite materials made of ceramic and metal, titanium compounds are used.

Structural parts

  • Wearing parts in soldering equipment, direct Contact mit Elektrolot bis 500 ° C
  • Springs in chassis of motor vehicles
  • in aircraft and spaceships for highly stressed parts, the need to remain light (Outer skin at supersonic speeds,, Compressor blades and other engine parts)
  • in steam turbines for the most heavily loaded blades of the low pressure part
  • in armor: Some sub-types of the former Soviet Union had pressure hull of a titanium alloy (of. B. Mike-Klasse, Alfa-Klasse, Papa class Sierra or class). In addition, titanium is, stronger than in the civil aviation, for use in military aviation. This led to, was produced at weddings that the Soviet military production, much of the world's promoted Titans both in Russia and installed again.
  • because of its low density in the production of level indicators and floats

Medicine

  • as a biomaterial for implants in the medical and dentistry (Dental Implants, Each year, approximately. 200.000 Piece in Germany alone) because of its excellent corrosion resistance in contrast to other metals. An immunological rejection response (Implantatallergie) does not exist. Also in crowns and bridges it is used because of the considerably lower cost as compared to gold alloys. In the surgical orthopedics with metallic prosthetic legs (Hip prostheses) and Hüftkopfersatz, After knee replacement osteoarthritis is it used en masse. The titanium oxide layer allows the solid growth of bone at the implant (Osseointegration) and thus allows the permanent installation of the artificial implant in the human body.
  • In the middle ear surgery, titanium is used as material for Gehörknöchelchenersatz prostheses and ventilation tubes for preferred use.
  • In neurosurgery have titanium clips (for aneurysm surgery) such largely displaced from stainless steel because of its favorable NMR properties.

Electronic

  • In 2002 brought the company Nokia, the mobile phone 8910 and a year later, the phone on the market in 8910, which have a housing made of titanium.
  • Im April 2002 brought the company Apple Inc. the notebook "PowerBook G4 Titanium" on the market. Large parts of the body were made of titanium and had the notebook in the 15.2″-Screen version at a thickness of 1″ a weight of only 2,4 kg.
  • Some ThinkPad series from Lenovo (formerly IBM) possess a titanium-reinforced plastic housing or a housing frame made of a titanium-magnesium composite.

Other application areas

  • Jewelry, Watches and eyeglass frames made of titanium
  • Coins with titanium core (of. B. Austrian 200 Schilling coins)
  • Titanium sublimation pump for the generation of ultra-high vacuum
  • Electroplating a carrier frame in the anodic oxidation of aluminum (ELOXAL)
  • As part of the standardized according CRISAT bullet resistant vests

Proof

TiO2+ with hydrogen peroxide forms a characteristic yellow-orange complex (Triaquohydroxooxotitan(IV)-Complex), also for the spectrophotometric detection is suitable.

Standards

Titanium and titanium alloys are standardized inter alia, in:

  • IN 17850, Output:1990-11 Titan; chemical composition
  • ASTM B 348: Standard Specification for Titanium and Titanium Alloy, Bars and Billets
  • ASTM B 265: Standard Specification for Titanium and Titanium Alloy, Sheets and Plates
  • ASTM F 67: Standard Specification for Unalloyed Titanium, for Surgical Implant Applications
  • ASTM F 136: Standard Specification for Wrought Titanium-6Aluminum-4Vanadium ELI (Extra Low Interstitial) Alloy for Surgical Implant Applications
  • ASTM B 338: Standard Specification for Seamless and Welded Titanium and Titanium Alloy Tubes for Condensers and Heat Exchangers
  • ASTM B 337: Specification for Seamless and Welded Titanium and Titanium Alloy Pipe

Safety

Titanium is a highly flammable powder, compact, safe. Most titanium salts are considered harmless. Volatile compounds such as titanium trichloride are highly corrosive, because they form with traces of water, hydrochloric acid.

Titanium tetrachloride is used in smoke grenades and smoke grenades; it reacts with atmospheric moisture to form a white smoke from titanium dioxide, addition of hydrochloric acid mist.

Biological disadvantages of titanium in the human body are not known at this time. Sun broke the previously manufactured from titanium hip joints or jaw implants, as opposed to nickel, no allergies.

Connections

While metallic titanium is reserved due to high production costs only demanding technical applications, has become a companion of everyday life, the relatively inexpensive and non-toxic paint pigment titanium dioxide. Virtually all of today's white plastics and paints, also contain titanium dioxide, food colors (it is in food as E 171 to find). But even in the electric- and engineering and, more recently, in the manufacture of high performance batteries for vehicle propulsion (Lithium-titanate-he must) titanium compounds are used.

  • Barium titanate, BaTiO3
  • Lithiumtitanat
  • Titan(III)-chloride, TiCl3
  • Titanborid, TiB
  • Titancarbid, TiC
  • Titannitrid, TiN
  • Titan(IV)-chloride, TiCl4
  • Titan(II)-oxid TiO
  • Titan(III)-oxid Ti2The3
  • Titan(IV)-oxide (Titanium White), TiO2
  • Titanium suboxides having a composition of TiO and Ti2The
  • Titan(IV)-oxide sulfate (Titanylsulfat), TiOSO4
  • Ferrotitan
  • Nitinol, ein Memory-Metall
  • Titanhydrid, THESE2

General
Name, Symbol,Atomic number Titan, You, 22
Series Transition metals
group, Period, Block 4, 4, d
Appearance silvery metallic
CAS-Nummer 7440-32-6
Mass fraction of derErdhülle 0,41 %
Atomic
Atomic mass 47,867 you
Atomradius (calculated) 140 (176) pm
Kovalenter Radius 160 pm
Electron configuration [It] 3d2 4s2
Work function 4,33 eV
1. Ionization 658,8 kJ / mol
2. Ionization 1309,8 kJ / mol
3. Ionization 2652,5 kJ / mol
4. Ionization 4174,6 kJ / mol
Physically
Physical State fixed
Crystal structure hexagonal (to 882 ° C, about bcc)
Density 4,50 g/cm3 (25 ° C)
Mohs 6
Magnetism paramagnetisch (\chi_{m} = 1,8 · 10−4)
Melting point 1941 K (1668 ° C)
Boiling point 3560 K (3287 ° C)
Molar Volume 10,64 · 10−6 m3/mol
Heat of vaporization 425 kJ / mol
Schmelzwärme 18,7 kJ / mol
Speed ​​of sound 4140 m / s at 293,15 K
Specific heat capacity 523 J/(kg · K)
Electrical conductivity 2,5 · 106 A/(In · m)
Thermal conductivity 22 W /(m · K)
Mechanically
E-Modul 105 GPa (= 105 kN/mm2)
Poissonzahl 0,34
Chemical
Oxidation states +2, +3, +4
Oxide (Basizität) TiO2 (amphoter)
Normalpotential -0.86 V (TiO2+ + 2 H+ + 4 and
→ Ti + H2The)
Electronegativity 1,54 (Pauling-Scale)
Isotope
Isotope NH t1/2 ZA ZE (MeV) ZP
44You {a son.} 49 a e 0,268 44Sc
45You {a son.} 184,8 my e 2,062 45Sc
46You 8,0 % Stable
47You 7,3 % Stable
48You 73,8 % Stable
49You 5,5 % Stable
50You 5,4 % Stable
51You {a son.} 5,76 my b 2,471 51In
52You {a son.} 1,7 my b 1,973 52In
NMR properties
Spin γ in
wheel·T−1·s−1
Itr(1H) fThe at
B = 4,7 T
in MHz
47You −5/2 1,508· 107 0,00209 11,3
49You −7/2 1,508· 107 0,00376 11,3
Safety
GHS Hazard Identification powder
02 – Leicht-/Hochentzündlich

GefahrH- and P-SätzeH: 250EUH: no EUH setsP: 222-231-422 Hazardous Information (Powder)Powder

Leichtentzündlich Reizend
Slightly-
flammable
Lovely
(F) (Xi)

R- and S-SätzeR: 17-36/37/38S: 26 (Powder)


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