Causes and Solutions of Cracks in Titanium Plates and Titanium-steel Composite Plates

Cracks are a frequent defect in the welding of titanium plates. Titanium weld cracks are cold cracks, mainly caused by hydrogen in the weld. The main sources of hydrogen are moisture and oil in the plate and welding wire, and the ambient humidity is the main reason for the increase of hydrogen in the weld.

Under the action of high temperature during welding, a large amount of hydrogen is dissolved in the molten pool. During the cooling and solidification process of the weld, hydrogen is easily escaped due to the rapid decrease in solubility. If the weld cooling rate is too fast, the hydrogen will not escape and remain in the weld, which will make the hydrogen in the weld supersaturated, so the hydrogen has to diffuse as much as possible, and promote further embrittlement of this area.

If there is a notch effect in this area and the hydrogen concentration is high enough, cracks may occur. Especially in winter construction, the ambient temperature is low, and the water vapor adheres to the AMS 4900 CP Titanium Sheet, which creates conditions for the hydrogenation of the weld. Because the titanium plate is too thin (1.2mm), the steel plate is relatively "warm", the temperature rises slowly, and the corresponding titanium composite layer weld is cooled too fast. During the cooling process, the residual hydrogen in the weld has no time to escape. It exists in the form of supersaturation in the weld, which eventually leads to the appearance of cracks.

Therefore, in the welding process of Grade 23 Ti-6Al-4V ELI Titanium Sheet, the surface of the base metal and welding wire should be carefully cleaned, and the ambient temperature should not be lower than 5 °C. During construction in winter, flame preheats the base steel surface, one is to remove the moisture around the weld; the other is to increase the temperature of the weldment and reduce the cooling rate of the weld.

What is a semiconductor target

The semiconductor Zirconium Sputtering Target is also a kind of sputtering target, which is mainly used in the semiconductor field. In several production links such as silicon wafer manufacturing, wafer manufacturing, and chip packaging of semiconductor chips, semiconductor targets are required for wafer manufacturing and chip packaging.

The main function of the semiconductor target is to make metal wires that can transmit information on the chip. The specific production process is to first use high-speed ion current to bombard the surface of different types of sputtering targets under vacuum conditions. The atoms on the surface of the target are deposited on the surface of the semiconductor chip layer by layer, and then the metal film deposited on the surface of the chip is carved into nanometer-sized metal wires, and the metal wires are used to connect the micro transistors inside the chip to achieve transmission. function of the signal.

Rolling method of titanium thick-walled tube, titanium seamless tube and titanium alloy tube

Titanium pipes can be divided into two categories: seamless pipes and welded pipes, which can be further divided into hot extruded pipes, hot rolled pipes, cold rolled pipes, welded pipes, and welded-rolled pipes. Production by skew rolling (two-roll or three-roll mill). Thin-walled seamless titanium tubes (small diameter) need to be cold-rolled or drawn. Some titanium alloys have low plasticity in cold rolling and are prone to cracking. In order to improve the rollability of Grade 2 Pure Titanium Tube, warm rolling can be used.

Industry requirements for thermal correction of titanium plates

In order to make the thermal calibration successful, the appropriate heating temperature, holding time, and forming pressure must be selected. The pressure exerted on the parts during thermal calibration is sufficient as long as the parts can be pressed against the mold. No matter how large the pressure is, it will not have much effect on the branch shape but may lead to the shape of the mold and the workbench. Therefore, the main factors affecting the thermal correction effect are temperature and time, and temperature is the decisive factor. In order to eliminate spring back satisfactorily, only at a certain temperature. The so-called thermal specification is mainly to determine the calibration temperature and time. In summary, the appropriate thermal specification for forming a certain titanium plate must ensure that the part meets the following basic requirements after shape correction: Grade 12 Titanium Sheet

1. The parts are well molded and basically do not need manual trimming. The shape, size, and surface quality meet the inspection requirements of Gr5 Ti-6Al-4V Titanium Plate parts;

2. The mechanical properties of the material are basically stable, and the main performance indicators at room temperature and operating temperature meet the regulations;

3. The residual stress inside the part is basically eliminated;

4. The average hydrogen content of the material after thermal correction does not exceed the allowable value of 150p. p. m;

5. The total thickness of oxide skin and gas permeable layer shall not exceed half of the allowable negative deviation of sheet thickness;

6. There is no change in the metallographic structure of the material, and there is no obvious growth and overheating of the grains;

7. Under the premise of meeting the above requirements, the temperature should be as low as possible, the time should be as short as possible, and the pressure should be able to ensure that the parts can be pressed.

What are the magical uses of titanium wire?

The performance of titanium is so excellent, the role of titanium and titanium products has become more extensive. Our most common titanium products are titanium plates, titanium rods, titanium standard parts, titanium dioxide, and even Gr5 Ti-6Al-4V Titanium Wire. With the continuous research and development of titanium, the application fields of titanium are becoming more and more extensive, and there are more and more titanium and titanium alloys and various titanium products. Let's take a look at the classification and uses of titanium wire.

Generally, according to whether the raw material is pure titanium or titanium alloy, it can be divided into pure titanium wire and titanium alloy surgical medical titanium wire; it can also be divided into α titanium alloy and near α type alloy, (α+β) type according to different components. Alloys, near-beta alloys, and beta alloys. It can also be classified according to the different properties of titanium wire, and it can also be classified according to other types, but the basis of other titanium wire classifications is relatively small, and it is adjusted according to the parameters of each industry.

Application of Titanium Standard Parts in Ocean Engineering

Titanium standard parts are the most widely used mechanical base parts. my country's fastener products are exported to many countries in the world, and fastener products from all over the world are also pouring into the Chinese market. Fasteners, as one of the products with the largest import and export volume in my country, are in line with international standards, which have important display significance and significance for promoting Chinese fastener enterprises to go global and promoting fastener enterprises to fully participate in international cooperation and competition. strategic significance. Fasteners are a general term for a type of mechanical parts used to fasten two or more parts (or components) into a whole. Also known as standard parts in the market. Due to the specifications, dimensions, tolerances, weights, properties, surface conditions, marking methods, and specific requirements of items such as acceptance inspection, marking and packaging for each specific fastener product, they are separately specified in several national (industry) standards. , such as Imperial, German, and American. Aerospace Grade Titanium Round Bar

Titanium standard parts are an important structural metal material. It has the advantages of low density, high specific strength, corrosion resistance, non-magnetic thermal conductivity, low five-toxicity, strong weldability, and good biocompatibility. It is widely used in aviation and aerospace. , petroleum, chemical, electric power, construction, sporting goods, medical and other fields. titanium exhaust flange

Titanium standard parts have important applications in many aspects of ships and marine fields, and are called "marine titanium screws". Seawater is highly corrosive, which requires materials used in the ocean to have good corrosion resistance; in addition, materials used in the ocean are subject to long-term erosion by seawater and periodic impact of waves, so the comprehensive mechanical properties of the material are also affected. higher requirements. Titanium has good mechanical properties and strong corrosion resistance. It is hardly corroded in seawater and humid environments. Its comprehensive performance is far superior to traditional metal structural materials such as stainless steel, aluminum alloy, and copper. It is an ideal material for ships and marine engineering. . For example, TA16 and TA17 titanium alloys have been used in Russian submarines, greatly improving the submarine's combat performance and safety and reliability. Titanium is also becoming more and more important in marine development, mainly involving offshore oil production equipment, seawater desalination, etc. In offshore oil production equipment, the equipment is often exposed to the corrosion of seawater, crude oil, chlorides and sulfides; it also bears working loads and wind and wave impacts.

Process of restarting arc after power failure during vacuum consumable smelting of titanium and titanium alloys

The process of restarting arc after power failure during vacuum consumable smelting of titanium and Grade 5 Ti-6Al-4V Titanium Plate includes the following steps: when restarting arc after smelting interruption, the smelting current is rapidly increased to 75-80% of the normal smelting current, and the current is maintained at this time. When the edge of the molten pool reaches the crucible wall, keep it for 2-3 minutes, and then quickly increase the smelting current to the normal smelting current. The advantage of this process is that the total arcing time is greatly shortened, the gap between the cooling volume of the ingot and the crucible wall is reduced, and the internal shrinkage cavity formed by the cooling and solidification of the ingot is avoided: when the melting current reaches the normal melting current When the smelting current is 75~80%, keep the smelting current for a period of time, so that the melting speed of the electrode and the solidified molten pool can be controlled more accurately, so as to avoid the instantaneous generation of a large amount of molten liquid flowing into the gap between the ingot and the crucible wall, or causing cold insulation defects .

The application status of large aerospace forging materials

Aviation forgings generally use materials with high specific strength and specific stiffness. Materials for large aviation forgings mainly include titanium alloys, ultra-high-strength steels, and aluminum alloys.

Titanium alloys for large aerospace titanium forging

Due to its high specific strength, specific stiffness, corrosion resistance, and other excellent properties, titanium alloys have been widely used in the aviation industry, and have significant effects on reducing the weight of aircraft structures and improving the service life of parts. Especially for military aircraft, some important structural components such as wing spars, bulkheads, landing gear, etc. are widely processed from titanium alloy forgings, which have high weight, large size, and cross-sectional area.

At present, the main grades of Ultra-Thin Titanium Alloy Sheets for aviation are TC4, TC18, TC21, TA15, TB6 (US Ti-1023 alloy), and so on. Among them, TC18 is suitable for the manufacture of large forgings due to the highest hardenability and is currently the most widely used in China. According to the demand of civil aircraft such as Boeing and Airbus, Russia has developed Ti-55531 titanium alloy based on TC18 alloy by reducing the content of Fe, which is easy to segregate. Ti-55531 is higher strength, with superior hardenability and a wider processing window, and is currently used on parts such as A380 aircraft hanger joints and landing gear struts

Application of titanium alloy materials in pharmaceutical production industry

The pharmaceutical industry is an important industry related to people's physical and mental health, including pharmaceuticals, medical machinery, sanitary materials and other fields, and occupies an important position in the national economy. Titanium alloy materials are widely used in the pharmaceutical industry because they are non-toxic and harmless, and have good compatibility with the human body. ASTM F136 Titanium Medical Wire     Gr7 Ti-0.2Pd Titanium Wire     Gr2 Pure Titanium Foil     Gr23 Ti-6Al-4V ELI Titanium Tube

In pharmaceutical production, because the production of medicines is inseparable from acids, alkalis and salts, pharmaceutical equipment is easily damaged by corrosion. The use of steel equipment not only cannot solve the problem of serious equipment corrosion, but also causes a lot of loss of human, material and financial resources, affecting normal production. The use of titanium equipment solves this problem very well.

In the production of several main commonly used drugs, the equipment made of titanium has good corrosion resistance and obtains considerable economic benefits.

1. Production of vitamin B1

In my country, the hydrogen chloride conversion method is often used to produce vitamin B1, and the finished product is dried by cyclone and separated by two cyclones. The medium is thiamine hydrochloride, the pH value is 2.5, and the temperature is 110 °C, which is highly corrosive. The original drying device was made of stainless steel, and the inner wall was corroded and perforated after more than a year of use, and seriously polluted the medicine.

After adopting titanium screw feeder, cyclone separator, vortex body, hopper and discharge pipe and titanium lining of exhaust box, the production qualification rate of vitamin B1 has been increased from the highest 95% to 100%, and the equipment has not been corroded for more than 7 years , the cost of titanium can be recovered in 3 months.

2. Vitamin C production

Vitamin C is sorbitol as raw material, fermented into sorbose with black vinegar bacteria, and then fermented with Pseudomonas to obtain low-concentration gulonic acid, which is converted into finished product by hydrogen chloride after concentration.

Titanium is very resistant to corrosion in high temperature coronic acid. In the production process of this product, a titanium tubular heat exchanger, a titanium DHC-500 disc sinking type automatic slag discharge centrifuge, and a TC4 cast impeller are used, and no corrosion has been found for many years.

3. Antibiotic production

The main raw material for the chemical synthesis of chloramphenicol (an antibiotic) is methyl dichloroacetate, which contains about 2% chlorinated alkene and trichloroethylene. If steel equipment is used in the refining process, it is prone to severe corrosion, and titanium is used instead. The equipment has been intact since its manufacture.

How is the super corrosion resistance of titanium alloy made?

Titanium alloys are widely used because of a series of excellent properties. However, titanium alloys have high friction coefficient, are very sensitive to adhesive wear and fretting wear, have poor wear resistance, are easy to ignite under high temperature and high-speed friction, and have relatively poor resistance to high-temperature oxidation. The shortcomings seriously affect the safety and reliability of its structure and greatly limit its application. Therefore, improving the surface properties of titanium alloys such as wear resistance, high-temperature oxidation resistance, and corrosion resistance is an urgent problem to be solved. In addition to improving the composition and preparation process of alloys, surface modification of Seamless Titanium Tube Grade 2 is currently the most effective method.

In recent years, electron beam surface treatment technology has developed rapidly. When the electron beam with high energy density acts on the surface of the material, the surface of the material has physical, chemical, or mechanical properties that are difficult to achieve by conventional methods, and the wear resistance and corrosion resistance of the material surface is significantly improved. and high-temperature oxidation resistance. A domestic engineering technology company used pulsed high-current and low-energy electron beams for surface treatment of grade 5 titanium round rods and achieved good results.

Welding Process and Welding Quality Inspection of Titanium Alloy

In order to avoid common welding defects and at the same time ensure the mechanical properties and corrosion resistance of the weld, when welding titanium and its alloys, a reasonable titanium alloy processing technology must be formulated to ensure the welding quality. At present, the commonly used processes for welding titanium and titanium alloys include argon tungsten arc welding, melting electrode argon arc welding, plasma arc welding, electron beam welding, laser beam welding, brazing, etc.

titanium welding filler wire is a commonly used welding method for welding titanium alloys, mainly used for the welding of titanium and titanium alloys with a thickness of less than 10mm. Manual tungsten argon arc welding has wide adaptability and reliable welding quality, but it has low welding efficiency and high labor intensity for thick plate welding. Melting electrode argon arc welding is more efficient than tungsten electrode argon arc welding and is mainly used for welding thick plates, but the welding process requires higher process parameters and a welding environment, otherwise, it is easy to generate pores. The thickness range of plasma arc welding is relatively wide, and it can be used from thin plates to thick plates, but attention should be paid to the damage to the nozzle during welding. Vacuum electron beam welding is also increasingly used for titanium welding. Because it is in a vacuum environment, it can obtain high-quality welded joints, but at the same time, because it needs to be welded in a vacuum chamber, the size of the workpiece is limited. Compared with the electron beam and plasma beam welding, laser welding has a molten pool purification effect, which can purify the weld metal, and the mechanical properties of the weld are equal to or better than those of the base metal. Brazing can also be used for some micro and precise parts.

Weld quality inspection:

The inspection standards and the specific welding seam inspection standards are strictly implemented in accordance with the drawing requirements and contract requirements.

inspection method:

Appearance inspection and inspection of the surface color of titanium welded joints are the primary control points for the inspection of welded joints. The surface of the welded joint is silver-white and golden-yellow as qualified. Blue, purple, gray and other colors are unqualified, and the surface needs to be treated or repaired.

The appearance quality of welds:

First of all, there should be no welding deformation. The workpiece will generally deform after welding. If the deformation exceeds the allowable value, it will affect the use. Furthermore, it is necessary to control the amount of misalignment and the excess height of the weld, which cannot exceed the tolerance range of the relevant standards. The surface of titanium alloy welds should be free of slag, spatter, cracks, weld bead, incomplete penetration, undercut, excess convex surface (fillet weld), poor forming, misalignment, burn through, arc damage, collapse, porosity, slag inclusion Such defects are visible to the naked eye.

Titanium alloy "space metal", widely used in high-end manufacturing

Titanium has excellent performance and has the reputation of "space metal". Titanium alloy is an important structural material. It is based on titanium and adds other elements such as vanadium, aluminum, molybdenum, and chromium. It is processed by smelting, forging, rolling, extrusion and other processes. It has low density and high specific strength. , The outstanding advantages of high heat resistance and strong corrosion resistance are widely used in high-end fields such as aerospace, petrochemical, national defense and military industry and medical biology.

Titanium Grade 2 Round Rods are widely used in aerospace due to their high corrosion resistance and high specific strength. In terms of hardness, titanium alloy is much harder than the other three alloys, and the tensile strength of titanium alloy is also the highest. Due to the weight factor also needs to be considered in the product structure, the density of zinc alloy is the largest and the specific strength is the smallest, and the specific strength of titanium alloy is higher. At the same time, due to its strong corrosion resistance and heat resistance, titanium alloys are widely used in aircraft engine parts, rocket and missile structural parts.

Titanium processing technology is complex, difficult, and has high technical barriers. The production process of titanium material includes titanium ingot or titanium alloy ingot obtained by melting and casting of sponge ASTM F136 6Al-4V ELI Titanium Bar, and then the company makes titanium material through deformation treatment and machining in forging, rolling and other links according to customer needs and application field requirements, and further. Processed into titanium equipment. The smelting, pressure processing and heat treatment of titanium are relatively difficult, the process is complex, and the technical content is high. Among them, the preparation steps of titanium sponge and titanium materials are more complex and difficult to prepare, which are the key links in the application of titanium. Sponge titanium and titanium The quality of the material directly determines the quality of titanium products.

Domestic casting process: vacuum consumable arc melting (VAR) and cooling bed furnace melting (CHM) in parallel. Due to the high chemical activity of titanium, it will react with hydrogen, oxygen, nitrogen and most refractories in the air in the molten state, so the casting must be carried out in a vacuum or an inert atmosphere. At present, there are two mainstream melting and casting processes in the world: vacuum consumable arc melting (VAR) and cooling bed furnace melting (CHM). The advantage of the VAR method is that the process is mature and the operation is simple. There have been many metallurgical defects such as inclusions and composition segregation in the alloy ingot, which seriously affect the reliability of the material. In recent years, Chinese titanium companies have introduced several electron beam cold hearth melting and casting furnaces and plasma cold hearth melting and casting furnaces from the United States and Germany, and gradually adopt the VAR method and the CHM method in parallel for casting.

Titanium alloys are classified according to their strength and characteristics

Titanium alloys can be divided into low-strength titanium alloys, ordinary-strength titanium alloys, medium-strength titanium alloys, and high-strength titanium alloys according to their different strengths.

1. Low-strength titanium alloys are mainly used for corrosion-resistant titanium alloy sheet, and other titanium alloys are used for structural parts called structure titanium alloys.

2. Ordinary-strength titanium alloys (~500MPa), mainly including industrial pure titanium, TI-2AL-1.5Mn (TCI), and Ti-3AL-2.5V (TA18), are widely used alloys. Due to its good price formation performance and weldability, it is used to manufacture various aerospace sheet parts and hydraulic pipes, as well as civilian products such as bicycles.

3. Medium-strength titanium alloy (~900MPa), the typical alloy is Ti-6Al-4V (TC4), which is widely used in the aerospace industry.

4. High-strength titanium alloy is composed of near-beta titanium alloy pipe and meta-stable beta titanium alloy with a tensile strength at room temperature above 1100MPa. It is mainly used to replace high-strength structural steel commonly used in aircraft structures. Its typical alloys are Ti-13V- 11Cr-3Al, Ti-15V-3Cr-3Sn (TB5) and Ti-10V-2Fe-3Al.

Titanium tableware​Relevant domestic and foreign regulations on quality and safety

Regarding the quality and safety status of titanium alloy kitchen utensils, there are relevant regulations and standards at home and abroad.

1. Relevant domestic laws and regulations

In the early stage, the only metal products subject to domestic laws and regulations were stainless steel and aluminum. There is no domestic product standard or industry standard for Gr2 Pure Titanium Foil, and there is no monitoring data. After the introduction of the new national standard system for food contact materials, the metal materials and products for food contact are regulated according to GB 4806.9-2016 "National Food Safety Standard - Metal Materials and Products for Food Contact".

2. Relevant foreign laws and regulations

In foreign countries, the supervision of titanium alloy kitchen utensils is mainly included in the legal system of metal materials for food contact.

In the United States, the supervision of tableware, food processing equipment, and food and beverage dispensing equipment is mainly carried out in accordance with ANSI/NSF standards. In NSF/ANSI 51-2009 "Food Equipment Materials", the minimum public health and hygiene requirements are specified for the materials contacting food in the production and operation food equipment, and all "food area" materials are required to be free from intentionally added lead. , arsenic, cadmium, mercury composition.

According to the notice issued by the Ministry of Health, Labour and Welfare of Japan, the general requirements for metal materials for food containers and packaging are: when Ti 15V-3Cr-3Sn-3Al Titanium Strip design and manufacture utensils, copper, lead, or their alloys that can be scraped shall not be on the utensils.

At present, at the EU level, there is no legally binding special directive or regulation for metal materials and products in contact with food. The European Council "Partial Agreement in the Field of Social and Public Health" only published a technical guideline on metals and alloys in contact with food in 2002.

Application Prospect of Titanium Alloy in Petroleum Industry

Titanium alloys are widely used in petroleum. In terms of current economic alternatives, there are mainly the following aspects.

At present, titanium alloy drill pipes of P110 steel grade have been produced in China. Compared with conventional ordinary steel S135 drill pipes, its advantages are as follows:

The large-reach well and horizontal well can be extended farther, and the density of titanium alloy is only 4.5g/cm3. The conventional density of drill pipe with the same wall thickness and length is 1.25g/cm3. The floating weight in the horizontal section of the drilling fluid is only 49% of that of the steel drill pipe. In this case, the frictional resistance is only about 50% of the ordinary drill pipe, and the friction torque of the pipe string is one of the core problems of the extended-reach well technology, which determines the maximum extension of the horizontal displacement, so the titanium alloy drill pipe It can be more beneficial to extended-reach wells and three-dimensional cluster horizontal wells. In the current situation of more and more factory drilling in China, titanium alloy drill pipe is used in a wider range.

Reduce ground equipment load

Due to the light weight of the titanium alloy forged ring the torque is reduced by nearly 50%, which effectively reduces the load of the ground top drive (turntable), which greatly reduces the probability of such damage, and the reduction of the load will also reduce the consumption of diesel.

Reduce hydraulic losses in joints

Titanium alloy drill pipe is light in weight and low in torque, and the processed drill pipe joint does not need to be strengthened like steel drill pipe. Usually, when φ127mm S135 drill pipe is used in horizontal wells, the inner diameter of the joint is reduced from φ82.55mm of G105 drill pipe to φ69. 85mm, titanium alloy drill pipe due to the reduction of torque, 80 steel grade drill pipe can achieve the strength effect of S135 steel grade at the same displacement (due to the 51% reduction in floating weight, the torque will also be reduced by 51%). The inner diameter of the drill pipe joint of X95 steel grade reaches φ88.9mm. The increase in the inner diameter of the joint can significantly reduce the cycle pressure loss.

Compared with the aluminum alloy drill pipe, the titanium alloy drill pipe has very prominent advantages. The performance of the titanium alloy and steel drill pipe joints is very similar, so the joint and the body can be made of the same material. In general, although the aluminum alloy drill pipe also has the characteristics of light weight, because the aluminum alloy is not resistant to wear and has low strength, the joint needs to be strengthened, and the joint is usually made of steel material, which results in a limited reduction in the weight of the drill pipe. Moreover, there is still a certain gap between the strength of aluminum alloy and high-strength steel, which can only reach about 2/3 of that of a complete set of titanium drill pipes. In addition, the material hardness of the aluminum alloy drill pipe is low, which causes serious scratches and wear on the body when the drill pipe collides with the well wall, so it is difficult to use. The titanium alloy drill pipe can effectively avoid this problem because the hardness of the body can be close to that of the steel drill pipe.

Titanium alloy parts processing occupies an important position in the machinery manufacturing industry

Titanium alloy has the advantages of low density, high specific strength, good corrosion resistance and good process performance, and is an ideal aerospace engineering structural material. Titanium and its alloys are replacing traditional aluminum alloys in many aerospace applications. Today, the aerospace industry consumes about 42% of total global production, and demand for titanium is expected to continue growing at a double-digit rate between now and 2010. The need for next-generation aircraft to take full advantage of the properties offered by titanium alloys is driving demand for titanium alloys in both the commercial and military aircraft markets. New models such as the Boeing 787, Airbus A380, F-22 Raptor, and F-35 Joint Strike Fighter (also known as Lightning II) use a lot of titanium alloys. Advantages of titanium alloy materials Titanium alloys have high strength, high fracture toughness, and good corrosion resistance and weldability. With the increasing use of composite structures in aircraft fuselage, the proportion of titanium-based materials used in the fuselage will also increase, because the combination of titanium and composite materials is far better than aluminum alloys. For example: Compared to aluminum alloys, titanium alloys can increase the life of airframe structures by 60%.

Because titanium alloys are more difficult to machine than ordinary alloy steels, titanium alloys are generally considered to be difficult-to-machine materials. The metal removal rate of a typical titanium alloy is only about 25% of that of most common steel or stainless steel, so machining a Titanium Grade 2 Round Rod workpiece takes about 4 times as long as machining a steel workpiece. To meet the growing demand for titanium machining in the aerospace industry, manufacturers need to increase production capacity and therefore need a better understanding of the effectiveness of titanium machining strategies. The machining of a typical titanium alloy workpiece starts with forging until 80% of the material is removed to obtain the final workpiece shape.

With the rapid growth of the aviation parts market, manufacturers have felt powerless, and the increased processing demand due to the low processing efficiency of titanium alloy workpieces has led to a significant tension in the processing capacity of titanium alloys. Some leading companies in the aerospace manufacturing industry even openly questioned whether the existing machining capabilities could complete the processing tasks of all new titanium alloy workpieces. Because these workpieces are often made from new alloys, machining methods and tool materials need to be changed. Titanium alloy Ti-6Al-4V titanium alloy has three different structural forms: a titanium alloy, a-b titanium alloy and b titanium alloy. Commercially pure titanium and a titanium alloys cannot be heat treated, but usually have good weldability; a-b titanium alloys can be heat treated, and most of them are also weldable; b and quasi-b titanium alloys can be fully heat treated, and generally also have Solderability.

The machining of titanium alloy parts occupies a very important position in the machinery manufacturing industry, and the machining of titanium alloy materials has always been a difficult point in the current processing technology. In order to meet the increasing demand for titanium alloy workpieces in aerospace, my country's titanium alloy cutting must make great progress. On the basis of domestic materials, machine tools and management conditions, it is important to further strengthen the optimization of the processing route of titanium alloy materials, the selection of processing parameters, and the improvement of processing efficiency and product quality, which are important to promote the development of the domestic titanium alloy industry and aerospace industry. factor. The inner cavity cylindrical surface finishing boring tool designed in this paper has a simple structure, is very convenient to manufacture and use, and solves the processing technology problem of the ball ring frame parts.

Problems Existing in the Processing of Titanium Alloy Fasteners

Corrosion problem. When installing titanium alloy fasteners, it is easy to form a certain gap, so that there will be surface paint inflow between metal air strikes, resulting in the fasteners being vulnerable to clothing during the production process. During subsequent use, the connection tightness will be affected. The main reason for the corrosion resistance of titanium alloy materials is that there is a protective oxide film on the surface. This film can effectively protect the titanium alloy inside the material from being oxidized, thereby improving the corrosion resistance of the titanium alloy material.

Problems in turning. Titanium alloy materials are difficult to process materials and have poor thermal conductivity. The heat generated during machining does not diffuse through the part and machine structure, but is concentrated in the cutting area, where there is a strong notch sensitivity, which can lead to chipping and deformation; and dull cutting edges can generate even higher heat And further reduce the tool life. The high temperature generated during cutting will also cause the workpiece to harden continuously, which will affect the surface integrity of the titanium and may lead to inaccurate geometric accuracy of the part and severely reduce its fatigue strength. Generally speaking, in In reasonable machining conditions, the turning process is not difficult. If it is for mass production, continuous cutting, and cutting with a relatively large amount of metal removal, carbide tools need to be used; while forming cutting or cutting requires steel tools. Make reasonable adjustments and use cermet cutters if necessary.

Precision issues in machining Titanium Flat Washers. The precision requirements for machinery will be higher. In mechanical production, because the tool is in a state of working wear during each production process, and it is calibrated according to the program, the density of titanium alloy fasteners is higher, and the tool is easily worn during the machining process. Under the state, the tool is still processed according to the program, and it is easy to cause the precision of the compact part to be affected during the processing. If the precision of the fasteners is not strictly controlled within the error range during the entire processing process, the titanium alloy and other materials cannot be tightly connected during the use process, which will have a certain impact on the subsequent use and improve The precision of titanium alloy fasteners in the machining production process is a major problem that needs to be overcome in the production process. For example, the fastener process product shown in the figure is a product made in a high-precision production workshop, and the connection performance of this product is better.

Pipe cutting and beveling of titanium pipes!

With the continuous expansion of the application field of titanium tube, the consumption is also rising. Our titanium tubes have been used in construction, in order to make construction more scientific, we can provide users with high-performance titanium tubes.

Research on refractory materials for casting molds has always been linked to the crucible materials for smelting titanium tubes and titanium alloy tubes. Based on kinetic reasons, the crucible materials need to be in contact with the titanium liquid for a long time during smelting, and the titanium liquid and the titanium liquid are in contact with each other for a long time. The contact time of the holding material is much shorter, so the available crucible material can be used as a mold material for titanium alloy pipes.

Materials that have been studied include carbides, nitrides, borides, sulfides, oxides, rare earth oxides, fluorides, oxyfluorides, sulfur oxides, and refractory metals such as W and Mo. Only very few materials have high chemical stability to titanium liquid, including ThO2, certain rare earth oxides, TaB2, Npc, some rare earth sulfides and some rare earth oxyfluorides.

Pipe cutting and beveling processing of Grade 2 Pure Titanium Tube; pipe cutting and beveling processing should be carried out by mechanical processing methods in special workplaces. When processing, use clean water with non-polluting medium for cooling to prevent oxidation. Processing tools should be dedicated and kept clean to prevent iron contamination. The processed nozzle should ensure that the surface is smooth and free of defects such as cracks and heavy skins. The maximum inclination deviation of the cut plane shall not exceed 1% of the pipe diameter.

Introduction to the application of titanium alloy materials in the military industry!

Most of the aircraft materials in the world are made of titanium alloy, but the structure of the aircraft using titanium alloy is more stable, which greatly reduces the weight of the aircraft and increases its stability of the aircraft.

Titanium rods and titanium alloys have the characteristics of low density, high strength, high-temperature resistance, and low-temperature resistance. Titanium and titanium alloys are essential materials for the military industry. For example, the American f-22 can conduct supersonic cruise flights for a long time. The point is to lose weight while maintaining your own strength. Without titanium, the fighter's long-range combat capability is greatly reduced. titanium sheet metal

On the naval side, titanium alloys can help submarines penetrate deep into the sea without being crushed by powerful seawater. For example, Russia's "Serra" class nuclear submarines are made entirely of titanium alloy and can dive to 600 meters, which makes Western submarines intimidating. Of course, it is also expensive because of the large-scale use of titanium alloys, known as "goldfish". In addition, titanium is non-magnetic, and warships made of titanium alloys can effectively resist magnetic mines and have strong corrosion resistance.

Five flaw detection methods for titanium materials----ultrasonic flaw detection

The frequency range of sound waves that people's ears can directly receive is usually 20Hz to 20kHz, that is, the sound (sound) frequency. The frequency below 20 Hz is called infrasound, and the frequency above 20 kHz is called ultrasonic. In industry, ultrasonic waves of several megahertz are commonly used for flaw detection. When the ultrasonic frequency is high, the propagation linearity is strong, and it is easy to propagate in solids, and it is easy to reflect when it encounters the interface formed by two different media, so it can be used for flaw detection. Usually, the ultrasonic probe is in good contact with the surface of the workpiece to be detected, and the probe can effectively transmit ultrasonic waves to the workpiece and can receive the ultrasonic waves reflected from the (defect) interface, convert them into electrical signals, and then transmit them to the instrument for processing. According to the speed of ultrasonic propagation in the medium (often called the speed of sound) and the propagation time, the location of the defect can be known. When the defect is larger, the reflecting surface is larger, and the reflected energy is larger, so the size of each defect (equivalent) can be checked according to the size of the reflected energy. Commonly used flaw detection waveforms include longitudinal wave, transverse wave, surface wave, etc. The former two are suitable for detecting internal defects, and the latter is suitable for detecting surface defects, but they have high requirements on surface conditions. 6al4v titanium sheet