Grinding treatment process titanium and titanium bar

Grinding treatment process titanium and titanium alloys are divided into : mechanical polishing , ultrasonic grinding, mechanical composite electrolytic polishing , grinding barrels .
A mechanical polishing : high chemical reactivity of titanium , low thermal conductivity, viscous , abrasive grinding machinery ratio is low, and easy to react abrasives , not for ordinary abrasive grinding and polishing of titanium , preferably good thermal conductivity superhard abrasives, such as diamond , cubic boron nitride , polishing line speed is generally 900 ~ 1800m/min appropriate, otherwise , the titanium surface grinding burns easily and micro- cracks .
Two ultrasonic grinding :titanium strip by ultrasonic vibrations , so that the surface to be polished and the abrasive grinding between the polished surface and the relative movement is to achieve grinding and polishing purposes. The advantage is that the polishing tool than the conventional rotary groove portion becomes easier to nest and narrow , but also a large grinding effect is not satisfactory castings .
3 Electrochemical Mechanical grinding : the use of conductive abrasive , electrolyte and a voltage is applied between the grinding and polishing the surface , the joint action by mechanical and electrochemical polishing , reducing the surface roughness to improve the surface gloss. The electrolyte was 0.9NaCl, voltage is 5V, speed 3000rpm/min, this method can only be grinding plane , polishing complex denture is still in the research stage.
4 barrels of grinding : the use of centrifugal barrel polishing generated revolution and rotation , so that the barrel of the denture and abrasive friction relative movement serve to reduce the surface roughness of the grinding purposes. Polishing automation, high efficiency, but can only reduce the surface roughness to improve the surface gloss medical titanium bars, poor precision grinding , deburring available denture fine and coarse grinding and before polishing .

The role of aluminum and gallium in titanium bar and titanium alloys in

Aluminum and gallium are titanium with a titanium and β form substitutional solid solution, mainly from the solid solution strengthening effect . The standard rule of titanium , industrial pure titanium in addition , almost all contain a certain amount of aluminum.

A2 relative to control due to the occurrence embrittlement , aluminum and other elements considered with the precipitation of a2 , the concept of aluminum equivalent . In a titanium alloy ,tittanium bar the aluminum equivalent of the following relationship :

AL `= AL +1 / 3Sn +1 / 6Zr +10 O` ≤ 8

Wherein , AL ` aluminum equivalent , AL, Sn, Zr weight percentage of these elements are in the alloy . O ` elements affecting the gap , also called oxygen equivalent . Oxygen equivalent to :

O `= O + C +2 N

Where O, C and N are both of these elements in the weight percentage of titanium . When adding titanium silicon , aluminum equivalent should be:

AL `= AL +1 / 3Sn +1 / 6Zr +4 Si ≤ 8

In the practical application of these formulas have some effect.

In the heat treatable alloys β , in order to prevent the produce ω phase metastable β phase decomposition when caused by brittle , you need a certain amount of aluminum , usually around 3%.

Adding aluminum in titanium alloys can be formed by the middle of alloys with high melting point metal to prevent intolerable metallic inclusions , the ingot ingredients evenly.titanium pipe If 78% Mo Mo - aluminum master alloy melting point of molybdenum can be reduced to about 1900 ℃.

There are currently being developed to Ti3AL and TiAL new high-temperature titanium alloy as the base , but the actual industrial production from a certain distance .

Common forms a stable element in titanium and titanium bar in

The main elements of a stable aluminum , gallium , germanium, lanthanum , cerium, neodymium and oxygen , carbon, nitrogen, boron , etc. Recently, some people think scandium and hafnium may also fall into this category . In the industrial application of the most widely used titanium alloy a stable element is aluminum. In recent years, in the development of nearly a gallium -based superalloy CKS growing importance titanium standard parts. Therefore , there will be described focusing on the role of aluminum and gallium .

1 Ti - Al binary system
The maximum solubility of aluminum in β titanium appeared in 1460 ℃, about 30%. The maximum solubility of aluminum in a titanium appeared in 1080 ℃, about a 11%, 550 ℃ , the solubility of aluminum in a titanium is about 7.5%. There will be two compounds , r phase and a2 -phase general phase diagram . r is an ordered phase based compound TiAL , with a face -centered tetragonal ( almost tetragonal ) lattice ; a = 4.005 Å , c = 4.073 Å , c / a = 1.0162. a2 -phase compound is an ordered group of Ti2AL having a hexagonal lattice , a = 5.8730 Å , c = 4.6543 Å , c / a = 0.8047. a2 phase transition phase can come from the β.

2 titanium - gallium
Titanium - Titanium binary gallium , gallium β titanium solution temperature maximum occurs at about 1500 ℃, approximately 38% (30 atomic% ) . Gallium in a maximum solid titanium in 940 ℃ about 17% (13 atomic% ) . Solubility decreases as the temperature decreases . General a2 phase is the phase diagram for the orderly phase -based Ti3Ga titanium whole distributor.

and the role of a β elements of titanium and titanium bar

Titanium is a very active metal element , and the effect of a number of elements which can occur, but can affect the properties of titanium and titanium alloys and titanium only those continuous or discontinuous elements of the solid solution is formed .

Role 1.β stabilizing element in titanium and titanium alloys in

β stabilizing elements include titanium located on the right side of the periodic table almost all transition elements and IB elements , about 30 species. The only real common dozen . Wherein the isomorphous β stabilizing elements molybdenum , vanadium, tantalum titanium stockists, niobium, eutectoid β stabilizing elements iron, chromium, manganese, copper , cobalt, nickel, tungsten, palladium and hydrogen. The unique role of hydrogen on titanium alloy will be described in relation to the impact of interstitial elements in titanium .

2.a role in stabilizing element in titanium and titanium alloys

The main elements of a stable aluminum , gallium , germanium, lanthanum , cerium, neodymium and oxygen , carbon, nitrogen, boron , etc. Titanium and titanium alloys in the industry 's most widely used is aluminum a stable element . Titanium aluminum can improve the tensile strength at room temperature and high temperature , high temperature has little effect on plasticity . Within the range of solubility , aluminum can effectively improve the elastic modulus of titanium , shear modulus,titanium sheet specific resistance and line expansion coefficient .

Effect of heat titanium bar on β titanium organization

β stabilizing element are different degree of reduction of titanium a + β / β transformation point and sequentially tantalum, niobium, molybdenum, vanadium, silicon, copper , chromium, manganese, iron incremented.
β stabilizing element are reduced titanium martensitic transformation start temperature. β stabilizing element is gradually increased , the point M can be reduced to titanium room temperature , the β -phase titanium alloy when rapidly cooled to room temperature region can be retained to a high temperature β -phase temperature . At this point the content of titanium element is critical concentration . titanium standard part Clearly, the critical concentration is the ability of β -phase stability of a measure of alloying elements. Β -stabilizing element Ti alloy phase is based tantalum, niobium, vanadium, tungsten, copper , molybdenum , nickel, cobalt, chromium, manganese , iron in increasing order . Isomorphous β stabilizing element element is weak , the eutectoid type element is stronger .

Titanium Titanium elements on recrystallization temperatures. Except cobalt and niobium , the manganese, iron , titanium vanadium were increased recrystallization temperature.

With the increase of β stabilizing element content , when the alloy rapidly cooled from β -phase region will appear different organizational changes , β stabilizing elements will affect the decomposition of metastable β phase in the aging process , and to type "C" curve to the right goes .

Eutectoid binary β stabilizing element in the form of titanium , there are eutectoid transformation equilibrium phase at room temperature with compounds ( except for tungsten outside ) . With the lower eutectoid reaction temperature , its ability to stabilize β phase is larger, the worse the eutectoid transformation of the active compound of the more difficult the phase appeared . Iron, manganese , tittanium bar chromium and other elements in the analysis of β -phase component that has been retained to room temperature, and generally can not be eutectoid transformation occurs . But like silicon , copper, nickel and other fast -eutectoid elements are not, they are prone to change and generate eutectoid pearlite lamellar organization a + compounds.

Titanium bar products are resistant to corrosion characteristics

Titanium is a metal having a strong tendency to passivation , and oxidation in air or in a neutral aqueous solution can quickly generate a stable oxide layer of protective film , even if the film is destroyed for some reason , can be quickly restored automatically. Therefore, titanium has excellent corrosion resistance in oxidizing , neutral medium , made ​​of titanium with titanium products also have strong corrosion resistance , widely used in the sealing surface material container equipment to address equipment sealing surface crevice corrosion problems.

Because of the great passivating titanium , in many cases, when in contact with dissimilar metals, corrosion is not accelerating , which may accelerate the corrosion of dissimilar metals .titanium standard parts When such a low concentration of non -oxidizing acids , if Pb, Sn, Cu or Ti alloy Monel galvanic contacts , the corrosion rate of these materials , and titanium is not affected. In the hydrochloric acid when contacted with a low Ti steel , the nascent hydrogen generated on the surface of titanium , titanium oxide film destruction , not only causes embrittlement of titanium , titanium and accelerate corrosion of titanium which may be due to a high degree of hydrogen active period.

Titanium iron content of certain media affect corrosion of iron in addition to the reasons for the increase in raw material reasons , often when soldering iron stain penetration weld , so that the local iron content increased weld , which when etching having a non-uniform properties. When using iron titanium support equipment, products made ​​of iron and titanium contact surface iron contamination is almost inevitable in the region accelerated corrosion of iron contamination , especially in the presence of hydrogen . When the titanium oxide film surface contamination to mechanical damage , the infiltration of a metal hydroxide , based on the temperature , pressure, etc. , corresponding to the occurrence of hydrogen diffusion , which have different levels of the titanium embrittlement . Therefore, titanium and moderate temperature and moderate pressure hydrogen system used to avoid surface iron contamination.

In general , titanium pitting does not occur . Made of titanium products also has anti- corrosion fatigue stability.tittanium bar Crevice corrosion resistance of titanium is better, especially Ti-0.3Mo-0.8Ni and Ti-0.2Pd alloy , so Ti-0.3Mo-0.8Ni and Ti-0.2Pd widely used to make industrial products.

The role of hydrogen in the interstitial elements of titanium and titanium bar

Titanium and titanium alloys in the interstitial elements mainly of hydrogen , nitrogen , carbon, boron and hydrogen and silicon. Their impact on the titanium and titanium alloys have poor . Described herein will focus on the role of hydrogen, oxygen , nitrogen ,titanium whole distributor carbon and boron.
The role of hydrogen in titanium and titanium alloys . In an industrial atmosphere , the maximum solid solubility of hydrogen in the β titanium is about 2.0% (49 atomic% ) . A titanium hydrogen of about 0.18% maximum solid (7.8 atomic% ) , in 319 ℃. This occurs at temperatures below the eutectoid transformation , its eutectoid point of approximately 1.62% ( 44% atom ) . β = a + γ
Eutectoid temperature of 281 ℃, hydrogen in the case of titanium the maximum solid solubility of a 0.13% (6.3 atomic% ) . γ phase is TiH2 compound having the face-centered cubic lattice , a = 4.44 Å . When the temperature dropped to a low 125 ℃, the solubility of hydrogen in a sharp decline titanium , about 0.001 to 0.0029% ( 0.05 to 0.14 atomic% ) . Should index, temperature and pressure in a hydrogen solubility in titanium and titanium- β by the solubility . Titanium and hydrogen interactions are reversible.

Hydrogen in titanium and titanium alloys in
Titanium and titanium alloys can cause hydrogen embrittlement various sources , causing low stress brittle fracture , therefore, can be used to prepare titanium and titanium alloy powder. Its approach is to titanium and titanium alloy materials ( such as chips , scrap , etc. ) in the 300 ~ 400 ℃ hydride embrittlement in a hydrogen atmosphere medical titanium plates, broken glass is made by milling the powder .

Effects of interstitial titanium bar the microstructure and properties of heat-treated

Nitrogen, oxygen, carbon , boron, titanium have increased a + β / β phase transition temperature . Content within the predetermined range , an increase of 0.01% each of the a + β / β transformation point values ​​were increased 5.5 ℃, 2.0 ℃, 2.0 ℃ ( more than 0.15 % of the total content of 0.15 ℃), 1.0 ℃, press nitrogen, oxygen ,titanium wire carbon, boron descending order . In terms of the content of titanium and titanium alloys maximum allowable calculated ( N <0.05% , carbon < 0.10% ) , the impact on the phase transition temperature on by oxygen , nitrogen, carbon descending order . Oxygen, nitrogen, carbon , boron, titanium starts can increase the recrystallization temperature .
Oxygen and nitrogen will promote the decomposition of metastable β phase , so that "C" shaped curve to the right goes . In addition, oxygen can promote the ω phase volume percentage.

Nitrogen, oxygen , carbon, titanium have increased the tensile strength at room temperature . By its strengthening effect of nitrogen , oxygen, carbon descending order . They will have an impact on the annealed titanium iodide room temperature tensile properties . Oxygen , nitrogen exist, the highest reinforcing effect , a carbon , oxygen, while adding the weakest effect .

Nitrogen, oxygen, carbon , boron, titanium can improve the elastic modulus , the maximum impact of carbon and boron . In addition to boron addition , oxygen , nitrogen, carbon impurity elements are titanium and titanium alloys . Therefore , all the provisions of their highest levels . For titanium alloy for low temperature applications due to oxygen , nitrogen and carbon in the titanium alloy can be improved plastic - brittle transition temperature , their contents should be minimized , especially the oxygen content . "ELI" grade titanium abroad for low temperatures ,titanium pipe meaning that the gap element content is lower .

Boron as alloying elements can not only improve the elastic modulus , and can refine the grain , usually in order to trace the use of titanium alloys .

Changes in titanium standard and titanium alloy on aging

Titanium and titanium alloy produced in the rapid cooling of the metastable phase during aging are balanced organization would like to change. The main phase transition phase metastable decomposition of β, tempered martensite, a supersaturated phase decomposition.medical titanium plates The transition process as well as the combination of aging and deformation of titanium and titanium alloy is heat strengthened basis.

Eutectoid transformation of titanium and only the fast formation of eutectic β stabilizing element in the system, it may occur under certain conditions. Such as Ti-Cu binary alloy components Hypoeutectoid appeared very small pearlite lamellar structure at a cooling rate of 100 ℃ / sec. When this alloy isothermal treatment at a temperature below the pearlite formation can also occur non-lamellar body of Bessie. In general, this analysis of the changes in the organization of the alloy ductility decreases.

There is a martensitic transformation in titanium, the applied stress and strain will promote these phase transition process. Experiments show that, in a certain β stabilizing element content of metastable β phase exists strain (or stress) caused changes. But the strain transformation products remains controversial, some people believe that the six-party martensite a `, some people think, but is a combination of mechanical twins.tittanium bar It was also reported that the Ti-Mo alloy and Ti-V strain orthorhombic martensite product is a ", and to facilitate this process the aluminum Anyway, strain to improve the uniform elongation of the material and increase the anti- tensile strength and the ratio between the yield strength.

Select titanium standard annealing process

In order to select a reasonable annealing process , we first observe the effect of heating temperature and cooling method on microstructure and mechanical properties of TC4 Titanium Alloy .

Test material 920 ℃ TC4 titanium alloy hot rolled bar , hot-rolled total deformation rate of about 80%, a + β / β phase transition point of 980 ~ 990 ℃. The sample at 1000 ℃, 950 ℃, 930 ℃, 830 ℃ , respectively, air cooled heat insulation , water and furnace cooling after 1 hour . Different ways of annealing on microstructure and mechanical properties are affected .

Which greatly affect the cooling rate on microstructure and mechanical properties of the four temperature microscopy . When water-cooled , 1000 ℃, 950 ℃ and 930 ℃ in equilibrium β -phase component were to happen martensitic transformation , β phase transformation to martensite a ` needle. At 1000 ℃ showed significant Wilcoxon organization whose mechanical properties of air-cooled 1000 ℃ data fairly . And water-cooled sample at 950 ℃ and 930 ℃, when the microstructure and characteristics are similar to air-cooled , but isometric is a ` needle β + martensite phase between a newborn titanium standard parts. At this point corresponds to the highest overall performance , and better creep resistance than air cooling organization . 830 ℃ thermal equilibrium β phase when the ingredients have not touch the M line , but the water-cooled intergranular β phase also found a very small needle transformation products , can only be distinguished by electron microscopy . But the structure of the product has not yet been measured needle . At this point the tensile strength and reduction rates are low. As furnace cooling , the sample was cooled slowly , long residence time at high temperature , sufficient for the polymorphic transformation , are all a phase become coarse . After cooling the furnace 1000 ℃ , a bulky sheet and a photo β phase grain boundaries in the original β -phase formed in a well strip thickness β grains within the original network , commonly known basket -like tissue . 950 ℃, 930 ℃ and 830 ℃ after furnace cooling , as a phase tends to a phase boundary in the original raw nucleation, growth , a microstructure are isometric and intergranular β phase . Tensile strength after 1000 ℃ lower than the furnace cooling air-cooled and water-cooled , higher tensile ductility . Overall performance in the other temperature furnace cooling are also lower than those in water and air .

In summary , in order to get the best TC4 titanium alloy strength and ductility performance, while there are good creep resistance and fracture toughness , can be incubated for 1 hour at 950 ℃ after air-cooled ( or water ) in the annealing process. In order to facilitate subsequent processing, metallurgical factory when the factory , TC4 titanium alloys are used in the 700 ~ 800 ℃ for 1 hour and air cooling technology medical titanium plate. For some large forgings , to ensure uniformity of performance , sometimes used by furnace cooling process .

Select the aging process titanium bar and titanium alloys

The purpose of titanium and titanium alloy aging treatment is to promote the metastable phase resulting solution treated a certain way decompose , causing strengthened. In general, this process can be described by a "C" type " time - - temperature changes" curve represents the relationship out .titanium axle Shape "C" shaped curve changes depending on the alloy composition . A heat-treatable alloys and a β β stabilizing element content of more binary alloy "C" shaped curve .

Determining an alloy aging process is generally based on age-hardening curve. It describes the different aging temperature , aging time and the relationship between the mechanical properties of the alloy . Mechanical properties of tensile properties at room temperature can also be used hardness or other properties. Select the aging temperature and time should be to get the best overall performance prevail , generally , a + β alloy aging temperature is about 500 ~ 600 ℃, time of 4 to 12 hours ; low alloy can be heat-treated β aging temperature , time long , approximately 450 ~ 500 ℃, 8 ~ 24 hours. Cooling air cooling are used .

In order to control the size of the precipitated phase , morphology and number , but also some multi -stage alloy aging . If TB1 alloy at 450 ℃, time 35 hours after once 560 ℃, 15 minutes time , a time when so produced a fine dispersed phase concentration, improved ductility after aging .

Requires the use of titanium for temperatures better thermal stability , often used in the above aging temperature .titanium wire Some of titanium in order to obtain good toughness and shear performance, but also the use of high temperature aging . This limitation is sometimes called stabilization treatment .

It should be noted , cold and low temperature pre-aging before aging are greatly accelerated the rate of decomposition of metastable β -phase , and to a relative dispersion enhancement . In some special conditions of use, can be heat treated to improve the tensile strength and elastic modulus β titanium alloy by cold deformation after aging treatment .

Heat treatment equipment and precautions titanium plate

On the principle of titanium and titanium alloy heating equipment , iron and steel used in heating oil furnace , induction furnace , gas furnace, electric furnace ( including carbon silicon rods, resistance wire heating chamber furnace , pit furnace ) , electric heating and oil heating the roller furnace and bath heaters , etc. can be heated titanium and titanium alloys . Required to maintain a neutral atmosphere in the furnace or in a weakly oxidizing atmosphere heating . Never allow the use of hydrogen is heated , try to avoid using a reducing atmosphere to prevent hydrogen absorption . When using direct injection of fuel heating to prevent the flame surface to prevent excessive oxidation or by carbon. When heat treated plate and bottom plate are separated to use , generally before heat treatment, heating , cleaning up the furnace must be strictly other metal oxide , the surface should not have oil and water.
In order to minimize the impact of the atmosphere , can be vacuum annealing furnace , vacuum hardening furnace . Require high vacuum degree of negative fourth power mmHg 1 * 10 can also be heated in a variety of inert gas in the furnace .surgical implant titanium But requires inert gas purity higher than 99.99%.
Titanium and titanium alloys after heat treatment of cooling air-cooled and water-cooled primarily and in some cases also used oil cooling, furnace cooling or air cooling .
Titanium and titanium alloys in a + β / β phase transition point is important to determine the basic parameters of the heat treatment process . Due to differences in the raw materials and the processing history , the chemical composition of titanium alloy , in particular the content of the different elements in the gap , a titanium between each batch + β / β transformation point is different . In practice, we found that the heat treatment , the heat treatment can enhance the number a + β and β titanium alloy, since the fluctuations in disguise point , when a heat treatment at a specified time and temperature , often different in different batches of titanium the microstructure and mechanical properties. Therefore, we recommend that each batch of titanium are to be measured a + β / β phase transition point , and accordingly within the recommended range of heat treatment process to select a specific process parameters.
Of titanium and titanium alloys - Determination of the phase transition point has metallographic , X-ray diffraction , high-temperature metallurgical method, resistance method , expansion method and computer law. Metallographic method used widely , but a long period , the impact of many factors . Expansion method and resistance method is relatively quick determination titanium rod. Calculation method is based on the effects of various elements on the titanium phase transition temperature to calculate the phase transition point . According to the average nominal composition of impurities always produce titanium and titanium alloy ingots and titanium calculated a + β β phase transition point and the measured value / is quite close .

The specific impact of the in-plane anisotropy titanium plate

1, the inner surface of the impact of sex on the sheet formability
Relative to the plate rolling direction is different in different properties , deformation of the cylindrical -shaped member is formed has become not axisymmetrical , there has been formed on the lug member . In addition to the emergence of the lug forming parts of the shape does not meet the requirements of ( sexual category is conformal ), the extent of allowable deformation is also a disadvantage .
Obviously, cylinder -shaped pieces of lug formed on the emergence of the cylinder is bound to shrink in the direction of the deformation of the cylinder uneven distribution of the large valleys , small lugs place, at the valley are more likely to wrinkle or scissors cut rupture. If the deformation is uniformly distributed , then this could have been avoided wrinkled or broken , or at least playing in some large deformation will occur.
Benli influence on the deformation of the lugs , except the performance outside the valley , it can also reflected in the lug direction ; performance is shaped pieces located on the lug direction , the material at the four corners of the die crack appears . This is due to the sudden wool lug width portion of the force exerted further deformation inevitably also need bigger, when it is large to a certain extent, the largest parts of the force - will die fillet crack .
Of course, non-axisymmetric parts , according to the specific circumstances of the part, select the appropriate cutting position, the nature of the use of the inner surface of the opposite sex ,medical titanium bar it becomes favorable factors , and sometimes can increase the allowable level of distortion.
The inner surface of the opposite sex conformal impact , but also the performance of the bending part . As the inner surface of the anisotropic material , ie the principal strain direction is not always the principal stress directions staff together in nature, so that the line is not bending to the plate and rolled or lateral bending pieces of the same , there has been intuitively seem should not happen wry .
The titanium surface of the opposite sex more significant adverse effects , in terms of setting is particularly prominent . Due to the different properties in different directions , even if the same molding stress , produce different rebound unloading cut , distortion of the shape of the forming member occurs , the original plane is also warped .
2, the influence of the surface of the opposite sex formability of sheet
As mentioned above ,titanium sheet the surface of the opposite sex typical performance is affected by the emergence of curvature force no longer remain flat plane . Obviously , the proper placement of wool during molding , it coincides with the curvature of the curvature formed by the surface of the opposite sex , molded parts will be beneficial to improve the degree of allowable deformation ; contrary, it will reduce the degree of allowable deformation. TCIM 1.5mm thick material such as a clear surface of the opposite sex , when the hole flanging, if the index is slightly thicker side to the opposite sex is part of the inner surface of the flange , then the limit factor than it is in the outer flange surface large 2.8%.

Chemical and physical properties of titanium plate

A4 is a Ti - Al binary alloy. Its tensile strength is slightly higher than the commercially pure titanium, do moderate-intensity range structural materials. Domestic mainly used wire. TA4 chemical composition of titanium, aluminum: 2.0 ~ 3.3, Fe 0.30, Si 0.15 C 0.10, N 0.05,surgical implant titanium 0.015 hydrogen, oxygen 0.15.

TA5 is a full a titanium alloy containing 4% aluminum and 0.005% boron. Its tensile strength than pure titanium high, but somewhat less plasticity, good weldability and corrosion resistance. The titanium alloy in the annealed state of delivery, can be used as structural materials seawater corrosion environments, has been successfully used in the shipbuilding industry. The chemical composition of titanium TA5, aluminum 3.3 to 4.3, boron 0.005, Fe 0.30 Si 0.15 C 0.10, N 0.04, 0.015 hydrogen, oxygen 0.15.

TA6 is a full a titanium alloy, containing 5% aluminum and silicon 0.015. Its high tensile strength than TA6, but the plastic than TA5 poor, good weldability and corrosion resistance. TA6 chemical composition of titanium, aluminum, 4.0 to 5.5, Fe 0.30, Si 0.15 C 0.10, N 0.05, 0.015 hydrogen, oxygen 0.15. TA6 main physical properties of titanium, density: 4.4 g / cm, a + β / β transformation point: 1000 to 1020 ° C, resistivity: 1.08 ohm mm2 / m.

TA7 is a titanium - aluminum - a whole tin ternary alloys, containing 5% aluminum and 2.5% tin. With moderate strength (80 kg / mm or so) in the annealed condition and sufficient ductility, good weldability. The material can be used as body temperatures below 500 ℃, short-term use temperature up to 900 ℃. When the titanium content is very low interstitial elements in the ultra-low temperature (-253 ℃) also has good toughness and overall performance, is an excellent ultra-low temperature titanium alloy. TA7 chemical composition of titanium: 4.0 to 5.5% aluminum, titanium standard part 2.0 to 3.0% tin, 0.3% iron, 0.15% silicon, 0.1% carbon, 0.05% nitrogen, 0.015% hydrogen, 0.2% oxygen.