The basic properties of titanium

The basic properties of titanium

Atomic structure
    Titanium is located in the periodic table ⅣB family, atomic number 22, atomic nuclei by protons and 22 neutrons 20-32 months, extranuclear structure arranged 1S22S22P63S23D24S2. 5x10-13 cm radius of the nucleus.
Physical Properties
    The density of titanium is 4.506-4.516 g / cm (20 ℃), the melting point of 1668 ± 4 ℃, latent heat of fusion 3.7-5.0 kcal / g-atom, the boiling point of 3260 ± 20 ℃, latent heat of vaporization 102.5-112.5 kcal / gram atom, critical temperature 4350 ℃, the critical pressure 1130 atm. Thermal and electrical conductivity properties of titanium is poor, similar or slightly lower than stainless steel, titanium superconducting, titanium superconducting critical temperature 0.38-0.4K. At 25 ℃, the heat capacity of titanium is 0.126 cal / gram atom · degree, enthalpy 1149 cal / g-atom, the entropy of 7.33 cal / g atom · degree, titanium is paramagnetic, permeability of 1.00004.
   titanium material has plasticity, high elongation titanium up to 50-60% reduction of 70-80%, but low intensity, not suitable for structural materials. The presence of impurities in titanium, a great effect on the mechanical properties, in particular interstitial impurities (oxygen, nitrogen, carbon) can greatly increase the strength of titanium, significantly reducing its ductility. Titanium as a structural material has good mechanical properties, that is, by strict control of impurities and where appropriate to add alloying elements to achieve.
Chemical properties
titanium plates for saleat higher temperatures, can react with many elements and compounds. Various elements, according to the occurrence of different reactions and titanium can be divided into four categories:
    The first category: halogen and chalcogen covalent bond with the formation of titanium compound and an ionic bond;
    The second category: transition elements, hydrogen, beryllium, boron family, clan carbon and nitrogen elements and titanium intermetallic compounds and limited solid solution;
    The third category: zirconium, hafnium, vanadium family and chromium family element scandium and titanium to generate an infinite solid solution;
    The fourth category: an inert gas, alkali metals, alkaline earth metals, rare earth elements (except scandium outside), actinium, thorium, which do not react with the titanium or substantially non-reactive.

History of titanium

History of titanium

   1791 British clergyman W. Gregor (Gregor) discovered a new metal elements in black magnetite. In 1795 the German chemist M. H. Carat Preuss (Klaproth) rutile in the study also found that the elements, and is named after the Greek god of the Titans. 1910 American scientist M. A. Hunter (Hunter) for the first time with a sodium reduction TiCI: Preparation of titanium. 1940 Luxembourg scientist W. J. Kroll (kroll) with magnesium reduction TiCl: prepared titanium. Since then, the magnesium reduction method (also known as the Kroll process) and sodium reduction method (also known as Hunt France) became the industrial production of titanium sponge method. In 1948 the United States out of the magnesium reduction process 2t titanium sponge, from reaching industrial scale. Subsequently, the United Kingdom, day / the former Soviet Union and China have also entered the industrial production, one of the major producing country of the former Soviet Union titanium, day / and the United States.
   titanium target is a new metal, because it has a series of excellent features, aviation, aerospace, chemical, petroleum, metallurgy, light industry, power, desalination, ships and everyday appliances are widely used in industrial production, which is hailed for modern metal. Titanium metal production from 1948 has only half a century of history, it is accompanied by the aerospace industry and developed new industries. Its development has withstood several ups and downs, this is because titanium and aircraft industry-related reasons. Overall, however, the speed of development of titanium is very fast, it is more than any other non-ferrous metals pace of development. This can be seen from the development of the world's titanium sponge industry: titanium sponge production scale of the 1960s 60kt / a, 70 years for 1lOkt / a, 80 years of 130kt / a, to 1992 has reached 140kt / a. Actual production in 1990 reached record levels, as 105kt / a. Currently, the world's titanium sponge production capacity of manufacturers and are listed in Table 1-1.
     After entering the 1990s, due to the reduced amount of titanium mesh and some Russian military and other countries to sell stocks of titanium sponge, so a few years ago a weak market. 1995 Titanium market began to rise, mainly due to a substantial increase in the amount of the civil B777 titanium and other civilian aircraft and golf clubs, titanium demand in 1996 reached a new high point. Experts predict that within the next few years the demand for titanium will continue to grow more substantial. At present, the main reason is to prevent the application of titanium expensive. It is expected that with the advancement of science and technology and titanium production process of continuous improvement, to expand production capacity and improve enterprise management level, to further reduce the cost of titanium products, is bound to open up a wider range of titanium market.

Titanium Application

Titanium Application

     titanium rod is a new structural material, it has excellent performance, such as low density (~ 4.5gcm-3), strength and fracture toughness than the ratio, strength and resistance to fatigue crack propagation ability, good low-temperature toughness, corrosion excellent performance, maximum operating temperature titanium alloy for some 550ºC, is expected to reach 700ºC. So it gets increasingly widely used in aviation, aerospace, chemical, shipbuilding and other industrial sectors, is developing rapidly. Light alloy, steel, etc. (σ0.2 / density) versus temperature, stronger than the titanium alloy is higher than other light metals, steel and nickel alloys, and this advantage can be maintained to about 500ºC, so some of the titanium is adapted manufacture of gas turbine components. Approximately 80% of titanium production for the aviation and aerospace industries. Airframe structural materials such as the US B-1 bomber, the titanium about 21%, mainly used in the manufacture of the fuselage, wings, skin, and bearing components. Airframe structural materials F-15 fighter, the titanium alloy with a capacity of 7000kg, accounting for about 34% of the weight of the structure. Boeing 757 aircraft structural parts, titanium or about 5%, with a capacity of 3640 kg. McDonnell Douglas (Mc-Donnell-Dounlas) produced by DC10 aircraft alloy with a capacity 5500kg, accounting for more than 10% of the weight of the structure. The amount of titanium in the chemical and general engineering areas: United States accounts for about 15% of its production in Europe accounts for about 40%. Due to the excellent corrosion resistance of titanium mesh and its alloys, good mechanical properties, as well as qualified histocompatibility, making for the production of biological materials such as prosthetic devices.

Titanium Performance

Titanium Performance

         1, low density, high specific strength
         The density of titanium is 4.51g / cm3, higher aluminum and less than iron, copper, nickel, but the head of the metal strength located
         2, corrosion resistance
         Titanium is a very reactive metal, which is very low equilibrium potential, thermodynamic corrosion tendency in the medium is large, but in fact the titanium is very stable in many media, such as titanium in an oxidizing, neutral or weakly reducing medium is corrosion resistance. This is because titanium has a great affinity for oxygen, in the air or an oxygen-containing medium, the surface of titanium to produce a dense, strong adhesion, inert large oxide film, protects the titanium substrate from corrosion, even if the mechanical wear will soon heal or regenerate. This shows that titanium is a metal with a strong passive tendencies. Medium temperature below 315 * c titanium oxide film remains this feature.
          3, good heat resistance
          New titanium alloy wire under long-term use of 600 * C or higher temperatures.

          4, good low temperature performance
         Its strength with decreasing temperature increase, but the plastic change is not large, good ductility and toughness at low temperature -196-253 ℃. Avoid cold brittle metal, is an ideal material for cryogenic vessels, tanks and other equipment.

          5, anti-damping properties.
          After medical titanium alloy subjected to mechanical vibration, electrical vibration, compared with steel, copper, its vibration damping longest, do take advantage of this performance titanium fork, ultrasonic vibrating element grinder medicine and advanced audio speaker vibration film.

          6, non-magnetic, non-toxic
          Titanium is non-magnetic metal, a large magnetic field will not be magnetized, non-toxic and with human tissue and blood have good compatibility, they were using the medical profession.

          7, the tensile yield strength of its proximity
         This performance titanium shows its yield ratio (tensile / yield strength) high, indicating that the metal material is too poor in the molding of plastic deformation, due to the ratio of yield strength and elastic modulus of titanium, causing titanium molding rebound capacity.

In addition to chemical impurities vanadium titanium tube

In addition to chemical impurities vanadium titanium tube

     Vanadium and seamless titanium tube and a small amount of impurities mainly VOCl3 discretion VCI4, their presence makes TC4 titanium tube yellow. In addition to the purpose of refining vanadium, not only for bleaching but also for oxygen. This is an extremely important part of the refining process.
   welded titanium tube and vanadium impurities ask discretion tube boiling point difference and relative volatility are relatively small, such as a two-component system titanium tube -VOCl3 boiling point difference is 10 ℃, the relative volatility of d = 1.22; and TC4 titanium alloy tube -VCl4 two lines boiling point difference of 14 degrees Celsius. Nevertheless, in theory, the use of physical methods are possible in addition to vanadium impurities, such as efficient use of the rectification column in addition to vanadium. The advantage of this method is that without the use of chemicals, refined enough continuous production process, easy to automate, isolated VCl4 VOCl3 and can be used directly. The disadvantage is that the energy consumption, large investment in equipment, but also need to address the structure of power kettle, put have not been applied in industry.
     In addition, TC4 titanium tube -V0Cl3 freezing point line two quite different points, a difference of about 54 degrees Celsius, and therefore can be used in addition to freezing crystallization VOCI3 but the energy consumption is frozen
Large, so it did not get industrial applications.
     For this reason is often used in addition to chemical vanadium. Vanadium is a chemical method in addition to adding a chemical reagent in a titanium tube, so VOCl3 (or VCl4) impurity selective reduction or selective precipitation alum form insoluble compounds and TC4 titanium alloy tube separated from each other or the selective adsorption of VoCl3 (or VCl4), vanadium impurities and TC4 titanium alloy tube separated from each other; or selective dissolution of VOCl2, so alum 7icld impurities and separated from each other. We can say that a low-technology equipment simply better long costs, labor conditions are good, but easy to achieve continuous operation in addition to vanadium process has not been established. This is also the TC4 titanium tube refining process requires study.

Classification of titanium alloys

Classification of titanium alloys

   titanium alloys is allotrope, melting point 1720 ℃, showed a close-packed hexagonal lattice structure, called α titanium at temperatures below 882 ℃; body-centered cubic structure over 882 ℃ character was called β titanium. The use of the different characteristics of the two titanium structures, adding appropriate alloying elements, so that the phase transition temperature, and gradually change the phase content of different tissues obtained titanium alloy bar. At room temperature, there are three titanium matrix organization, titanium will be divided into the following three categories: α alloy '(α + β) alloys and β alloys. China respectively TA, TC, TB, said.
α titanium
It is a single phase alloy consisting of α-phase solid solution, either at ambient temperatures or at higher temperatures the practical application, are the α phase, organizational stability, wear resistance higher than that of pure titanium, high resistance to oxidation. At a temperature of 500 ℃ ~ 600 ℃, and maintains its strength and creep resistance, but can not be heat strengthened, not high temperature strength.
β titanium alloy
It is a single-phase alloy consisting of β-phase solid solution, that is not heat-treated after having a high strength, hardening, aging alloy has been further strengthened, the room temperature strength of up to 1372 ~ 1666 MPa; but poor thermal stability, and should not be used at high temperatures .
α + β titanium alloy
It is duplex alloys, has a good overall performance, good organizational stability, good toughness, ductility and high temperature deformation properties, can better thermal pressure processing, can be quenched, aging of the alloy strengthening. Strength after the heat treatment higher than the annealed state of about 50% to 100%; high temperature strength, long-term work at a temperature of 400 ℃ ~ 500 ℃, the thermal stability is inferior α titanium alloy.
The most commonly used three kinds of titanium alloy is α and α + β titanium alloy; α titanium alloy machinability best, α + p titanium followed, β titanium worst. α titanium codenamed TA, β titanium codenamed TB, α + β titanium codenamed TC.
   Titanium can be divided according to use heat-resistant alloys, high-strength alloys, corrosion resistant alloy (Ti - molybdenum, titanium - palladium alloys, etc.), low-temperature alloys and special features alloy (Ti - Fe hydrogen storage materials and titanium - nickel shape memory alloy), etc. . Table typical composition and performance of the alloy.
Titanium heat treatment can be obtained by adjusting the heat treatment process and the organization of different phases. Generally considered fine equiaxed has good ductility, thermal stability and fatigue strength; needle tissue has a high rupture strength, creep strength and fracture toughness; equiaxed and needle hybrid organization has good overall performance.

Progress Titanium

Progress Titanium

   In recent years, countries are developing a new type of low-cost and high-performance titanium, titanium alloy into the civilian efforts to make positive industry has huge market potential. New progress of titanium alloy is mainly reflected in the following aspects.
(1) high temperature titanium alloy
   Successfully developed the world's first high-temperature titanium alloy is Ti-6Al-4V, using a temperature of 300-350 ℃. Then have developed a use temperature of 400 ℃ of IMI550, BT3-1 and other alloys, as well as the use of a temperature of 450 ~ 500 ℃ of IMI679, IMI685, Ti-6246, Ti-6242 alloy. Has been successfully used in military and civil aircraft engines in the new high-temperature titanium alloys have British IMI829, IMI834 alloys; United States of Ti-1100 alloy; Russia BT18Y, BT36 alloy. Table 7 as part of the country's new high-temperature titanium alloy maximum operating temperature [26].
In recent years, the use of foreign fast solidification / powder metallurgy technology, fiber or particle-reinforced composites developed high temperature titanium alloy as the development direction, so that the use of temperature titanium alloy can be increased to more than 650 ℃ [1'27'29'31 ]. American McDonnell Douglas by rapid solidification / powder metallurgy technology Qi successfully developed a high-purity, high-density alloy at 760 ℃ its strength equivalent to the strength of the current room temperature titanium alloy used in .
   (2) titanium-based alloy aluminum compounds.
   Compared with the general titanium, titanium-aluminum-based compound sodium Ti3Al (α2) and TiAl (γ) intermetallic compounds biggest advantage is a good temperature performance (maximum operating temperatures of 816 and 982 ℃), strong antioxidant, anti-good creep resistance and light weight (density of only 1/2 of a nickel-base superalloy), these advantages make it the aero-engine and aircraft structural parts of the most competitive materials in the future.
   (3) resistant titanium alloy. Conventional titanium alloys have a tendency to burn alkoxy under specific conditions, which limits its application to a large extent. In view of this situation, countries have launched a study of flame titanium and made some breakthroughs. Qiang country developed the Alloy c (also known as Ti-1720), the nominal composition of 50Ti-35v-15Cr (mass fraction), is a kind of continuous burning insensitive resistant titanium alloy, have been used in the F119. BTT-1 and BTT-3 for the Russian developed resistant titanium alloy, both Ti-Cu-Al alloy, has a very good thermal deformation process performance, which is made available for complex parts [26].
   (4) medical titanium.
   Titanium non-toxic, high light, strength and excellent biocompatibility, is ideal for medical metallic material, used as human implants implanted and so on. Currently, in the medical field is still widely used Ti-6Al-4v ELI alloy. But the latter will precipitate a very small amount of vanadium and aluminum ions, reducing its cellular adaptation and possibly cause harm to humans, this issue has caused widespread concern in the medical profession. Qiang States early in the 20th century the mid-1980s began to develop non-aluminum, vanadium-free, biocompatible titanium, which is used to orthopedic surgery. Japan, the United Kingdom also done a lot of research work, and made some new progress.

Classification and characteristics of titanium products

Classification and characteristics of titanium products

Iridium coating of titanium alloys, tantalum products
      Resistance to oxygen evolution anode, oxygen evolution reaction is mainly used, especially for acid electrolyte, such as a certain concentration of sulfuric acid electrolyte, ultra low oxygen can be used to put oxygen electrolysis, also resistant to chlorine corrosion, can be used to put oxygen and put chlorine electrolysis, such as sea water electrolysis. it is acidic medium oxygen evolution reaction better electrode materials, limited in this environment can be used for the electrode material. The coating has been applied to an organic electrolytic electrode, such as cysteine, glyoxylic acid, succinic acid, etc., can be used for the indirect oxidation of the organic electrolytic Cr3 ++ → Cr6 + electrolysis, for oxidation of sewage treatment of organic matter and toxic substances in water, as CN- transformation. But also in the electroplating industry, as an auxiliary electrode, such as Cr-plated auxiliary anode, auxiliary anode copper, electrolytic zinc auxiliary anode cathodic protection anodes and other aid.
Ruthenium - Iridium - three yuan titanium anode coating
    The anode coating for high-containing hydroxide electrolyte oxygen corrosion resistant, suitable for ion-exchange membrane electrolysis. Coating indicators:
1, discharge potential at 4000A / m2 current density of 1.18 V (SCE).
2, strengthen life (coating weight loss) 1.02mv / 4 hours. cm2, life protection over five years, has been used in the industrial power slot.
Ruthenium - Iridium - Tin - Titanium (Ru-Ir-Sn-Ti) four yuan coating electrodes.
1, low chlorine evolution potential, the potential is too small, at 2000A / m2 current density of chlorine discharge potential is not greater than 1.12V, overvoltage less than 20mv.
2, the polarization of less than 30mv / 10 units of current density.
3. Strengthening long life 0.5N H2SO4,1A / cm2 current density, life of more than 1500 minutes.
    More than three indicators are better than industry regulations indicators (industry indicators: potential 1.13 volts, polarization 40mv / 10 units of the current density, strengthen life of more than 1000 minutes). The coating has been widely used in the chlor-alkali industry,, the actual life of up to 8 years.
Titanium-based anode PbO2
      The anode is a titanium mesh matrix, the above plating β-PbO2, which is characterized by oxygen high, application in acidic solution, especially some of the organic electrolysis, anodic oxidation reaction requires high potential, but also to minimize the release of oxygen side effects, PbO2 electrode material is relatively good. Perchlorate as electrolysis, sewage treatment oxidation of organic matter, such as phenol-containing wastewater. It can also be used as a general release oxygen electrode, although its oxygen high, but its price is relatively Ta-Ir electrode is much cheaper, so organic electrolysis, electroplating, sewage treatment and get so many applications.
Qi Xin Titanium titanium dioxide production of lead products combined with good strength and long service life. Produce a variety of cylindrical shapes, mesh and so on.

Precision alloy material objects will become mainstream metal structures

Precision alloy material objects will become mainstream metal structures

Precision titanium alloy bar structure and its products are mainly used in auto parts, communications equipment, aviation equipment, high-speed locomotives and other precision machining accuracy and quality structure, there are strict requirements of the sophisticated areas, in addition, also be applied pillar industries in electrical equipment manufacturing, precision mechanical and electrical equipment manufacturing, and many other national economic development. Titanium is a new structural material, it has excellent performance, such as low density (~ 4.5g cm-3), strength and fracture toughness than the ratio, strength and resistance to fatigue crack propagation ability, good low-temperature toughness, resistance excellent corrosion properties, the maximum operating temperature of some titanium alloys for 550ºC, is expected to reach 700ºC. So it gets increasingly widely used in aviation, aerospace, chemical, shipbuilding and other industrial sectors, is developing rapidly. Light alloy, steel, etc. (σ0.2 / density) versus temperature, stronger than the titanium alloy is higher than other light metals, steel and nickel alloys, and this advantage can be maintained to about 500ºC, so some of the titanium is adapted manufacture of gas turbine components.
In 2011, China's total output of titanium alloy wire die-casting metal casting structure structure of total production increased from 65.68% in 2000 to upgrade to 85.90%, China has become an important area of development of metal structures. At the same time, the world's titanium manufacturing trend to accelerate the transfer to China, where the formation and cost advantages of industrial clusters is one of the main driving forces, titanium China era is opening. Materials and aircraft driven by growing mutual aviation material has been playing a leading and fundamental role. According to the use of different parts, aerospace materials can be divided into airframe materials and engine materials. In the development of modern materials science and technology, the titanium tube body material is not only to lead the development of the aircraft itself, but also led to ground vehicles and spacecraft progress. The development of the engine materials are constantly driving force for industrial innovation and energy industries.
In the automotive sector, the Chinese auto industry continued to grow rapidly in this century, the annual compound growth rate of 18.5%. In 2011, though China's auto industry slowed down, but the country's macroeconomic development trends, the future second and third tier cities will become the focus of economic development. Data show that line the city's markets do fall two to three percentage points per year, three-line market is growing two to three percent per year, by 2020, the total amount of third-tier Chinese city car will account for about 55% of the national share.
In the field of communications, as of the end of February 2012, China's mobile phone users exceeded 1 billion mark, of which 3G subscribers reached 140 million, and in the high-speed growth. Currently 3G subscriber penetration has exceeded the number of seventh overall mobile phone users, and is expected to increase to 20% of the level in the third quarter of 2012. Titanium and oxygen in the air and water vapor high affinity for the sake of making titanium and titanium alloy surface at room temperature to form a high-level stability, strong adhesion permanent oxide film TiO2, and the quality of the titanium oxide film in damage can regenerate immediately after. Because this layer of film to improve its corrosion resistance makes titanium used in the chemical industry, processing industry and power generation industry and other industries in today's harsh environment extensively.

Relationship quality and heat-treated titanium watches

Relationship quality and heat-treated titanium watches

The quality of titanium watches, mainly determined by the pickling process after heat treatment, but if the first step of a heat surface oxide formed thick skin or tissue is uneven, it does not improve with pickled surface smoothness and uniformity. So to pay full attention to the heating surface cleaning or heat treatment before heat treatment.

Ingredients titanium alloy wire, alloy many dozens, often adding cadmium, lead, iron, titanium, copper and other elements, but titanium element content for case strap myself how much I do not know. In recent years there has been 1% copper, 0.1% titanium andtitanium alloy sheet containing aluminum alloy containing 22% overall for outstanding creep strength, low-temperature plasticity and superplasticity. Battery case, printing plates, roof and household hardware and so spend titanium, so to make it expensive watch case and strap it up.

If the surface oxide scale thickness unevenness titanium plate, thick and thin places where the underlying substrate metal surface finish or different, titanium tube surface and pickling and surface oxide scale dissolution site of attachment of the base metal by acid different levels of erosion, so that the steel surface is uneven. Therefore, when the heat treatment is heated, so as to form an oxide skin must be uniform. To meet this requirement, involving the following conditions must be noted.

And stainless steel compared to titanium in weight and hardness are more advantages for the manufacture of the case, with only about half as heavy section steel table, and less prone to scratches. Accordingly, its production cost is also stainless times. Titanium in the medical field also has a wide range of applications, using it to create "artificial bone" flesh and blood can play a role in supporting and strengthening never need to replace (other metal materials can not do), so enjoy the "pro bio-metal "in the world, with its manufacture watches of course, do not worry about skin allergies and other problems.

If attached to the surface when the workpiece is heated oil, the site of attachment of the scale thickness and the scale and the thickness of the other portion of different composition, and will produce carburizing. Subcutaneous base metal oxide is partially cemented will seriously eroded acids. When the combustion of heavy oil burner initially discharged droplets, if attached to the workpiece, a great impact. Operating heavyweight fingerprints attached to the workpiece when will be affected. Therefore, the bath as high officials do not directly touch the titanium pieces, do not make a new piece stained with oil. The gloves must Daiqing Jie. If the surface during cold lubricants attached, must be fully cleaned with warm water and then skim trichlorethylene degreasing agent, caustic soda solution, and then subjected to heat treatment.