Defects that are prone to occur in titanium alloy forgings:

1. Segregation type [i] defects

In addition to β segregation, β spot, titanium-rich segregation and strip α segregation, the most dangerous is interstitial α stable segregation (type I α segregation), which is often accompanied by small holes and cracks around it, containing oxygen, nitrogen and other gases , is more brittle. There is also aluminum-rich α stable segregation (type II α segregation), which also constitutes a dangerous defect due to cracks and brittleness, and also reduces the thermal stability and other properties of the alloy.

2. Inclusions

There are inclusions on the surface of the billet, and cracks are often formed along the inclusions during forging, or obvious foreign bodies appear after the forging is corroded, most of which are metal inclusions with high melting point and high density. It is formed by the high melting point and high density elements in the titanium alloy composition that are not fully melted and left in the matrix (such as molybdenum inclusions), and there are also carbide tool chippings or inappropriate electrode welding processes mixed in smelting raw materials (especially recycled materials). The smelting of Titanium Industrial Rod generally adopts the vacuum consumable electrode remelting method [ii]), such as high-density inclusions left by tungsten arc welding [iii], such as tungsten inclusions, and titanium compound inclusions. Titanium alloy forgings with inclusions are not allowed to be put into use.

3. Holes

The holes do not necessarily exist alone, but may also exist in a plurality of clusters, which will accelerate the growth of low-cycle fatigue cracks and cause premature fatigue failure.

4. Cracks

Mainly refers to forging cracks. Titanium alloys have high viscosity, poor fluidity, and poor thermal conductivity. Therefore, in the process of forging deformation, due to large surface friction, obvious internal deformation unevenness, and large temperature difference between inside and outside, it is easy to get inside the forging. A shear band (strain line) is generated, and cracking occurs in the direction of the maximum deformation stress in severe cases.

5. Overheating

The thermal conductivity of titanium alloys is poor. In addition to overheating of forgings or raw materials caused by improper heating during hot working, it is also easy to cause overheating due to thermal effects during deformation during forging, causing changes in microstructure and overheating Widmanderin [iv] ].

In order to ensure the quality of titanium alloy forgings, in addition to strictly controlling the quality of raw materials, attention should also be paid to the ultrasonic flaw detection of forging blanks and semi-finished products to prevent some deformation and physical properties during subsequent heating and processing.

Development in the field of titanium and titanium alloy products

Titanium alloys were widely used in the aerospace field in the early days, mainly in the production of aircraft engines or pneumatic components. Later, with the continuous and in-depth development of technology, titanium alloys have entered the lives of ordinary people, and titanium alloys are also used in factories or household devices. Now countries and institutions are scrambling to develop new titanium alloys, which have the characteristics of low cost and high performance. In recent years, the new development of titanium alloys is mainly concentrated in the following aspects.

(1) Medical titanium alloy.

Titanium alloys have low density and good biocompatibility. They are ideal medical materials and can even be implanted into the human body. Titanium alloys previously used in the medical field contain vanadium and aluminum, which can cause harm to the human body. However, recently, Japanese scholars have developed a new type of titanium alloy with good biocompatibility, but this alloy has not yet been mass-produced. It is believed that such high-quality alloys can be widely used in daily life in the near future.

  (2) Flame retardant titanium alloy.

Titanium-based alloys that can resist combustion under certain pressure, temperature and air flow rate are resistive titanium alloys. The United States, Russia and China have successively developed new resistance titanium alloys. The United States applies these resistance titanium alloys to engines. Because these titanium alloys are not sensitive to combustion, the stability of the engine can be greatly improved.

  (3) High temperature titanium alloy.

Combining the rapid solidification method and the powder metallurgy method, the titanium alloy prepared by the fiber or particle reinforced composite material has excellent high temperature mechanical characteristics. The service temperature limit of high temperature titanium alloy is much higher than that of ordinary titanium alloy. At present, a new type of high-temperature Grade 3 Pure Titanium Sheet has been prepared in the United States.

Problems in CNC titanium machining!

Because the thermal conductivity of titanium processing is small, the heat generated during cutting cannot be dissipated and will be stored in the tool, so the wear on the tool will increase.

Because of the large chemical activity, when the cutting speed increases, cutting heat will occur, and the temperature of the cutting part will increase, so the activity will increase and the wear on the tool will increase.

Because the continuous deformation causes chips to be generated, the cutting resistance of the cutting edge increases, and the tip is prone to chipping and wear.

Because the elastic modulus is small, the machining material is prone to great deformation during cutting, especially when machining thin workpieces, 6al4v titanium round bar the machining accuracy will be reduced and chattering will occur.

Cold Rolling Properties of TC6 Titanium Alloy Sheet

TC6 titanium alloy plate is a martensitic Ti-Al-Mo-Cr-Fe-Si series α+β two-phase thermally strong titanium alloy with good comprehensive properties. Its nominal composition is Ti-6Al-2.5Mo-1.5Cr -0.5Fe-0.3Si, the α/β transition temperature is between 960 and 1000 °C. In addition to the advantages of high specific strength and good corrosion resistance of ordinary titanium alloys, this alloy also has good comprehensive mechanical properties at room temperature and high temperature, and the operating temperature can be as high as 450 °C. Parts, can also be used to manufacture aircraft bulkheads, joints and other parts. In China, a lot of work has been done on the processing technology and performance optimization of TC6 titanium alloy forgings, castings, pipes and bars, etc., but there is less research on TC6 alloy sheets. The basic process parameters of cold rolling processing of TC6 sheet were studied, and the cold rolling processing performance of TC6 sheet was studied.

The TC6 titanium alloy ingot used in the experiment is obtained by three times of smelting in a vacuum consumable electric arc furnace, and its β transition temperature is 975-985 °C. , Fe0.41, Si0.29, O0.10, Zr<0.01, C<0.01, N<0.01, and the remainder of Ti. The TC6 ingot used in the experiment was opened in the β phase region, and the α+β two-phase region was forged into a slab. The slab is hot rolled and opened at the β transformation temperature, and rolled to 3.5mm in the α+β two-phase region. After intermediate annealing and pickling, the cold rolling work hardening experiment is carried out. When the processing rate increases by 5%, a piece of 200mm long test material is cut from the head of the plate, and the remaining plate continues to be rolled. Repeated rolling and sampling until the Grade 3 Pure Titanium Plate has edge cracks or surface cracks. Then the cut 200mm experimental materials with different processing deformations were tested, and the thickness, width, edge cracks, microstructure and mechanical properties of the experimental plates were tested respectively.

Common titanium alloy materials and titanium products preservation requirements:

1) For the site or warehouse where Grade 12 Ti-0.3Mo-0.8Ni Titanium Sheet products are stored, it should be selected in a clean and tidy place with smooth drainage, away from factories and mines with harmful gases or dust. Weeds and all debris should be removed from the ground to maintain the cleanliness of titanium materials.

2) Do not stack with acid, alkali, salt, Shimin soil and other materials that are corrosive to titanium materials in the warehouse. Different varieties of titanium materials should be sorted and stacked to avoid confusion and contact with corrosive objects.

3) Titanium alloy materials such as large titanium tubes, titanium rods, thick titanium plates, large diameter titanium tubes, and titanium forgings can be stacked in the open air.

4) Small and medium-sized titanium, titanium plates, titanium rods, medium-diameter titanium tubes, titanium wires, etc. can be stored and placed in a shed with satisfactory ventilation.

5) Small-scale titanium materials, thin titanium plates, titanium strips, small-diameter or special-shaped titanium tubes, various cold-rolled and cold-drawn titanium materials, and high-priced and easily corroded metal products can be stored and stored.

6) The warehouse is required to maintain a suitable storage background, pay attention to ventilation in sunny days, and close it to prevent moisture in rainy days.

7) The warehouse should be selected according to the geographical conditions, and the ordinary closed warehouse should be used if it is considered appropriate, that is, the warehouse with the roof and the wall, the door is tightly closed, and the ventilation device is installed.

Classification of targets

According to the application, it mainly includes targets for semiconductor applications, targets for recording media, targets for display films, optical targets, and superconducting targets. Among them, Titanium Nitride Sputtering Target for semiconductor applications, targets for recording media, and display targets are the three types of targets with the largest market scale.

Titanium Rotary Sputtering Target shapes include cuboid, cube, cylinder, and irregular shapes. The cuboid, square and cylindrical targets are solid. During the sputtering process, the annular permanent magnet establishes an annular magnetic field on the surface of the target, forming an etched area on the annular surface with equidistant distances between the axes. The disadvantage is that the film deposition thickness is uniform. The performance is not easy to control, and the utilization rate of the target is low, only 20%~30%. At present, the rotating hollow tube magnetron sputtering target is popularized at home and abroad.

Internal defect correction process of titanium alloy tube and titanium tube weld

Internal defects of Grade 2 Pure Titanium Pipe welds Incomplete penetration refers to a defect that the workpiece is not fused with the weld metal or the weld layer. Incomplete penetration weakens the working section of the weld, resulting in severe stress concentration, which greatly reduces the strength of the joint, which often becomes the source of weld cracking. The slag inclusion weld contains non-metallic slag, which is called slag inclusion. Slag inclusion reduces the working section of the weld, resulting in stress concentration, which will reduce the strength and impact toughness of the weld.

When the stomatal weld metal is at high temperature, it absorbs too much gas (such as H2) or gas (such as CO) due to metallurgical reactions inside the molten pool, which cannot be discharged in time when the molten pool cools and condenses, and forms inside or outside the weld. Holes are stomata. The existence of pores reduces the useful working section of the weld and reduces the mechanical strength of the joint. If there are penetrating or continuous pores, it will seriously affect the sealing of the weldment. Cracks During or after welding, the partial rupture of the metal in the area of ​​the welded joint is called a crack. Cracks can occur in the weld as well as in the heat-affected zone on both sides of the weld. Sometimes it happens on the outside of the metal, sometimes it happens inside the metal.

Usually, according to the different mechanisms of cracks, they can be divided into two categories: hot cracks and cold cracks. Hot cracks occur during the crystallization process from liquid to solid in the weld metal, and most of them occur in the weld metal. The main reason for this is the presence of low melting point substances (such as FeS, melting point 1193 ° C) in the weld, which weakens the connection between the grains. . When the welding parts and electrodes contain a lot of impurities such as S and Cu, thermal cracks will easily occur. Hot cracks are characterized by spreading along grain boundaries. When the crack penetrates the surface and communicates with the outside world, it has a significant tendency to hydrogenate. Cold cracks occur during the post-weld cooling process, mostly on the base metal or the fusion line between the base metal and the weld. The main reason for its occurrence is that the heat-affected zone or the weld constitutes a quenching structure. Under the effect of high stress, the internal fracture of the grain is caused. When welding easily quenched titanium alloys with higher carbon content or more alloying elements. , most prone to cold cracks. Too much hydrogen melted into the weld can also cause cold cracks. Crack is one of the most dangerous defects. In addition to reducing the load-bearing section, severe stress concentration will occur. During use, the crack will gradually expand and eventually cause damage to the component. Therefore, this disadvantage is usually not allowed in the welding layout, and once found, it must be removed and re-welded.

Complete Annealing Process of Titanium and Titanium Alloys

In the complete annealing process, the purpose of complete annealing of titanium and titanium alloys is to obtain a stable, plastic or microstructure corresponding to certain comprehensive properties. Recrystallization mainly occurs in this process, so it is also called recrystallization annealing. In addition, there are also changes in the composition, morphology, and quantity of a-phase and β-phase. Most a and a+beta titanium alloys are used in fully annealed condition. The two-phase region of all-a-type titanium alloys is very small, and recrystallization occurs mainly during the complete annealing process. The annealing temperature is generally selected to be 120 to 200°C below the a+β/β transformation point. Too high temperature will cause unnecessary oxidation and grain growth, and too low temperature will cause incomplete recrystallization. The cooling rate has little effect on the structure and properties of such alloys, and air cooling is generally used.

In addition to recrystallization during annealing, near-a titanium alloys and a+β titanium alloys also have changes in the composition, quantity and morphology of a-phase and β-phase, and it is also complicated to determine the annealing process. For the delivery state of the metallurgical plant, a stable and plastic structure is mainly required. The annealing temperature is generally selected to be 120-200°C below the a+β/β transformation point, and the cooling method is also air-cooled. However, for the annealing of the product before the final use, it must be determined through experiments according to the influence of the annealing process on the microstructure and mechanical properties.

As for metastable beta titanium alloys, complete annealing is also solution treatment. The annealing temperature of the metallurgical plant before leaving the factory is generally selected to be 80 to 100 °C above the a+β/β transformation point. Within the recommended full annealing process range, the specific process should be determined experimentally based on the processing history of the material, the actual chemical composition, and the equipment used. In order to avoid unnecessary oxidation, the process should be selected with the lowest temperature and shortest time under the premise of meeting the performance requirements.

The beta annealing process has appeared in recent years. The grade 7 titanium alloy plate and a+β titanium alloy are heated in the β phase region and then air-cooled, and a needle (or flake) a is precipitated on the coarse β grains. This structure corresponds to higher fracture toughness, creep resistance and notch sensitivity, but reduces plasticity indicators such as section shrinkage. It can be used as appropriate in situations where this performance is emphasized.

In addition, for some alloys, when it is required to improve the performance stability of long-term operation at the service temperature, a second annealing higher than the service temperature, or isothermal treatment is often used, such as TC9 and tc6 alloys.

Development characteristics of titanium alloy materials and processing technology of titanium products

Due to the high manufacturing cost of titanium alloys, in order to reduce costs, the competitiveness of titanium alloys in the entire metal material market is improved at lower prices. Titanium is widely considered to have unparalleled superior properties compared to other materials, but the price of titanium is often prohibitive for consumers, especially automakers. The emergence of high-quality and low-cost titanium alloys will certainly contribute to the popularization and application of titanium and Ultra-Thin Titanium Alloy Sheet.

From the application status at home and abroad and the development of titanium processing technology, the plastic processing technology of titanium and titanium alloys will develop in the following directions in the future:

1) High performance, that is, to develop alloys with higher service temperature, higher specific strength, higher specific modulus, better corrosion resistance and wear resistance.

2) Multifunctional, that is to develop titanium alloys with various special functions and uses, such as high damping, low expansion, constant resistance, high resistance, anti-electrolytic passivation and hydrogen storage, shape memory, superconductivity, low modulus biomedical and other titanium alloys, and further expand the application of titanium and titanium alloys.

3) Deepen the research on traditional alloys, improve the practical properties of existing alloys, and expand the application scope of traditional alloys through the improvement of equipment and processes.

4) Adopt advanced processing technology and large-scale continuous processing equipment to develop continuous processing technology, direct rolling technology, cold forming technology and near-net forming technology to improve the production efficiency, yield and product performance of ASTM F67 Gr2 Titanium Plate.

5) Reduce costs, develop alloys that contain no or almost no precious metal elements, and add cheap elements such as iron, oxygen and nitrogen, and develop titanium alloys that are easy to process and form, easy to cut, and inexpensive to alloy elements and master alloys. Develop titanium alloys, use prohibited materials, and improve the recovery rate and utilization rate of prohibited titanium. This is particularly important for reducing the cost of civilian titanium alloys.

6) Using advanced computer technology to simulate the deformation and processing process of the workpiece, predict the evolution of the metal microstructure, and even predict the mechanical properties of the product (yield strength, tensile strength, elongation and hardness, etc.). ), and design or improve molds and tooling; analyze and process test results, reduce test volume, improve work efficiency, and reduce development costs.

Russia develops new technology to enhance antibacterial effect of titanium alloy

The Russian State Research University of Technology and other Russian scholars have developed a new technology that enables the antibacterial effect of astm b348 titanium rod, one of the key materials for advanced surgery. Implants processed according to the new method will significantly speed up and facilitate recovery from trauma, the researchers say.

The mechanical properties and resilience of damaged bones decline significantly with age, and such damage requires long-term treatment. The use of implants made of unmodified metals and alloys can lead to complications that may require a second surgical procedure afterward. Materials that can inhibit bacterial activity help in vivo implant surgery to be safer and more reliable. For this reason, Russian scholars have developed a method of spraying antibacterial coatings on Ti-Zr-Nb, one of the Titanium Alloy Rectangular Tube.

Experiments showed that treatment according to the new method completely inhibited the growth of E. coli on the implant surface. At a low dose of silver (about 0.037 mg/L), it is completely safe for the body and achieves a significant antibacterial effect. The "strike" against the bacteria is carried out by silver ions, the researchers said. The scientists chemically synthesized the nanoparticles that released them in a complex alcohol solution, which made them only about 10 nanometers in size. Thanks to this, silver is deposited in the pores of the material to a depth of 60 nanometers, greatly improving the durability and antimicrobial effect of the coating.

Titanium alloy rod hot extrusion forming process!

The thermal conductivity of the titanium alloy billet is low, and the temperature difference between the surface layer and the inner layer will be large during hot extrusion. When the temperature of the extrusion cylinder is 400°C, the temperature difference can reach 200~250°C. Under the combined influence of suction strengthening and the large temperature difference of the billet section, the metal on the surface and the center of the billet has completely different strength and plasticity, which will cause very uneven deformation during the extrusion process, and produce a large additional tensile force on the surface layer. Stress becomes the source of cracks and cracks on the surface of extruded products. The hot extrusion process of titanium rectangular rod and titanium alloy rod products is more complicated than that of aluminum alloy, copper alloy and even steel, which is determined by the special physical and chemical properties of titanium rod and titanium alloy rod.

The research on the metal flow dynamics of industrial titanium alloys shows that there are great differences in the metal flow behaviors of different alloys in different temperature regions. Therefore, one of the main factors affecting the extrusion flow characteristics of titanium rods and titanium alloy rods is the heating temperature of the billet that determines the state of mental transformation. Compared with the temperature extrusion of the P-phase region, the metal flow in the a-phase region or the P-phase region is more uniform. It is difficult to obtain extruded products with high surface quality. Until now, the extrusion of medical titanium rod had to use lubricants. The main reason is that titanium will form eutectic with iron-based or nickel-based alloy mold materials at 980 degrees and 1030 degrees, which will cause strong mold wear.

What are the technical requirements for titanium rods?

Titanium rod has good physical and chemical properties, low density, light weight, non-magnetic, high strength, good corrosion resistance, it has good mechanical properties and welding performance, Baoji titanium rod is widely used in chemical equipment, seawater In desalination, ship parts, electroplating industry, etc., the corrosion resistance of titanium is 10 times that of ordinary stainless steel, and titanium metal is a metal with low human rejection, so the processed parts of medical titanium rods are widely used in human implantation and medical equipment. use. medical titanium bar

skills requirement:

1. The chemical composition of titanium and titanium alloy bars shall comply with the provisions of GB/T 3620.1. When the purchaser re-inspects, the allowable deviation of the chemical composition shall comply with the provisions of GB/T 3620.2.

2. The diameter or side length of the hot-worked bar and its allowable deviation shall comply with the provisions of Table 1.

3. After hot processing, the bar is turned (ground) and cold-rolled. The allowable deviation of the diameter of the cold-drawn bar should meet the requirements of Table 2.

4. The out-of-roundness of the bar that has been turned (ground) after hot processing should not be greater than half of its dimensional tolerance.

5. The indefinite length of the processed bar is 300-6000mm, and the indefinite length of the annealed bar is 300-2000mm, and the fixed or double length should be within the range of the indefinite length.

How to deal with burrs in titanium plate processing

The method of this mechanical treatment is: bury the Grade 1 Pure Titanium Plate in a lot of abrasives, add some grinding and polishing compounds dissolved in water, use the principle of oscillation to mix the abrasives with the material, and continuously ask the workpiece to scour, the surface and edges of the workpiece. Corners, etc. are ground by abrasives and then polished. This technology can be used for deburring, chamfering, rust removal, descaling, flattening and finishing processing for metal parts of various sizes and shapes.

Abrasives can be alumina (including fused, sintered or natural), corundum, plastic, quartz, ceramics, etc., and can be a single species or a mixture of several. The shapes of these abrasives can be made into diagons, cylinders, diamonds, etc. The reason why preformed abrasives are made first is that it is more economical and abrasive than any shape and natural shape materials. According to the shape and size of the workpiece, use abrasives of different shapes and sizes. Rolling abrasives include pumice, quartz, granite leather corners, shells, iron filings and ceramic fragments. The size of the abrasive particles should be larger or smaller than each hole in the part. The amount of content in the drum is also an important factor affecting the quality of the agricultural surface of the parts. The number of people in the drum is usually 70% of the drum volume. The solution in the drum should be added to about 95% of the drum volume (note: when adding acidic solution to the drum, you should add enough water first, and then add acid to avoid corrosion of parts during the rolling process, because the time increases , the concentration of the contained solution gradually decreases, and even loses its effect.

The processing time of Grade 7 Titanium Sheet can range from several minutes to several hours. The key is to choose the abrasive, which is determined by experiment. Only in this way can a uniform, bright appearance be achieved. After processing, the workpiece is unloaded together with the abrasive, which is screened by the separator and taken out, and the recovered abrasive can be continuously returned to the machine for processing. Oscillating finishing machine is divided into two categories: single machine and online, which are selected according to production needs.

Application of Titanium in Onshore Oil and Gas Exploration and Development

Oil and natural gas exploration and development can be divided into land mining and offshore mining. The oil and natural gas stored in the crust accounts for roughly 60% on land and 40% offshore. The oil and gas in the offshore crust such as the Bohai Sea and the South China Sea are also exploited. significant.

Before the industrialization and large-scale application of titanium alloys, the commonly used logging instrument casings were made of 45 steel, 40Cr steel, and 30 MoVNb steel, but none of them could meet the needs of modern technical logging, modern high-tech oil and gas exploration And development requires that the metal casing of the logging tool can not only withstand the pressure of > 98 MPa, but also resist the corrosion of underground crude oil and various media, and in the logging, it must also have a small absorption rate of natural gamma rays. , and should not have a shielding effect on the geomagnetic field. From these performance requirements, Ti 15V-3Cr-3Sn-3Al Titanium Strip is good materials for making logging tool housings.

How to use the mechanical and physical properties of titanium in titanium processing

(1) The elastic modulus of titanium is relatively low relative to its tensile properties, so a larger springback allowance must be considered in the pressing and roller operations. It is precisely because of the lower elastic modulus that in order to achieve the same degree of stability, the cross-section of the titanium part is slightly larger than that of the same steel part.

(2) Titanium is easy to machine, but considering its seizure tendency (larger than stainless steel) and low thermal conductivity, it is necessary to appropriately improve the commonly used machining technology and the design of threads and bearing surfaces. At least a rigid machine tool, a sharp tool, a slow speed, a large amount of cutting, and room for chip removal are also recommended. It is also recommended to use a large amount of cooling lubricant.

(3) The thermal expansion coefficient of titanium is 75% of that of carbon steel. Special attention should be paid to this when combining these two materials in equipment design and manufacture.

(4) Since titanium is an active metal, when heated to above 600 °C, it is easy to combine with oxygen in the air, so it is generally not recommended for long-term use of Titanium Alloy Threaded Rod above this temperature.

(5) When the temperature of industrial pure titanium exceeds 150~200℃, the mechanical strength decreases rapidly.

(6) The diffusion rate of hydrogen in titanium exhaust flange is faster than that of oxygen, so before hot working, the heating furnace used should have a slightly oxidizing atmosphere, so that although a relatively thin oxide film will be produced, it avoids the possible damage caused by hydrogen. Deep pollution.

(7) The softer industrial pure titanium plate is easy to be cold formed after annealing treatment; the harder industrial pure titanium and Ti2.5Cu require medium temperature processing, and the processing temperature for Ti6Al4V is preferably 600~700℃.

(8) Composite plates can be obtained by explosive welding of thin titanium plates and thick steel plates, which can be used to manufacture high-pressure, high-temperature vessels and heat exchangers. But it is not economical to use it to replace the whole titanium or the titanium lining plate of the suit.

Technical extrusion characteristics of titanium screw hydrostatic

Hydrostatic extrusion technology has a history of nearly a hundred years. However, in the process of large-scale and industrialization, the development speed has been slowed down due to the limitation of higher-strength structural materials. The practical application of this technique has been facilitated with advances in materials science. The use of hydrostatic extrusion technology to extrude Titanium Hex Nut has outstanding advantages. In recent years, superconducting materials have developed in the direction of large sections. Due to the increasingly high requirements for continuous steepness, the size and weight of the ingot must be increased. In this way, it is difficult to use ordinary extrusion equipment, and the use of hydrostatic extrusion technology has many advantages.

During metal processing, it is desirable that the workpiece be in a state of triaxial compressive stress, as this facilitates the plastic deformation of the metal and eliminates surface cracks and defects in the product. In addition, it is also required to be in a good lubrication state during processing to reduce the loss of function. If the hydrostatic extrusion technology is used, the above two purposes can be met.

1. The hydrostatic extrusion of Titanium Elbow is in the process of frictionless deformation. The friction between the ingot and the extrusion cylinder is the main obstacle to metal deformation. When hydrostatic extrusion is used, the high-pressure liquid separates the ingot from the wall of the extrusion cylinder, and at the same time, some high-pressure liquid enters the die hole, and the extruded product is also separated from the die wall. Therefore, the friction coefficient can be as low as 0.01 or less, which also greatly reduces the power loss and improves the surface accuracy of the product.

2. Increase the length of the bad ingot of the titanium screw In the traditional extrusion method, 50% of the extrusion force is used to overcome the friction force between the ingot and the extrusion wall. The magnitude of the friction force is proportional to the toughness of the ingot. Therefore, the length of the ingot is limited. If hydrostatic extrusion is used, it is in a frictionless extrusion process, therefore, the length of the ingot can be increased. For example, for the same tonnage extruder, the output of hydrostatic extrusion can be more than three times higher than that of ordinary extrusion.

Application of Titanium in Pharmaceutical 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. Grade 1 Pure Titanium Plate is widely used in the pharmaceutical industry because it is non-toxic and harmless, and has good compatibility with the human body.

In pharmaceutical production, because the production of drugs 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 welding filler wire solves this problem very well.

The processing flow of titanium rod from sponge titanium to rough is as follows:

(1) Compression electrode, the sponge titanium is pressed through a press to form a dense sponge titanium pressed block electrode

(2) Vacuum casting, under the conditions of 1700~1800℃ and -103pa, the above-mentioned sponge titanium pressed block electrode is vacuum casting three times;

(3) Open the billet. Under the condition of 1000 ℃, the billet is opened by the hydraulic press, and the Z is finally pressed into a square billet; when the billet is opened, it should be noted that the life of the titanium rod is reduced due to the high pressure, so when the closed die F9 Titanium Forging method is used. When forging titanium rods, closed die forging must strictly limit the volume of the original blank, which complicates the preparation process. Whether to use closed die forging or not, it must be considered in terms of interest and process feasibility. During open die forging, the loss of burrs accounts for 15%-20% of the weight of the blank. The technological waste of the clamping part (if necessary to keep this part according to the die Titanium Threaded Forged Fitting conditions) accounts for 10% of the weight of the blank. The relative loss of burr metal is usually The weight of the blank has been reduced and increased. Some forgings with asymmetric structures, large cross-sectional area differences, and difficult to fill local forgings. The burr consumption can be as high as 50%. Closed die forging has no burr loss, but the blanking process is complicated and needs to be added. More transitional grooves will undoubtedly increase auxiliary costs.

(4) For the first rolling, under the condition of 970~980℃, the roughness of cylindrical shape is initially rolled by a rolling mill

(5) The second rolling, under the condition of 950 ℃, use a rolling mill to make a blank. There are many rolling methods, which can be classified according to different characteristics. Extrusion is classified according to the characteristics of metal flow and deformation, including forward extrusion, reverse extrusion and special extrusion. Special extrusion includes hydrostatic extrusion, continuous extrusion, lateral extrusion, co-extrusion, compound extrusion, sheath extrusion, peeling extrusion, water-sealed extrusion, bitter die extrusion, powder extrusion, semi-extrusion Melt extrusion, liquid extrusion, etc. Extrusion is classified by temperature, including hot extrusion, warm extrusion and cold extrusion. Hot extrusion and cold extrusion are the two major branches of extrusion. Hot extrusion is mainly used in metallurgical industry systems, which is commonly known as extrusion; cold extrusion is used in mechanical industry systems; the development of warm extrusion is relatively late, and the scope of application is also small.

The influence of laser welding on the surface treatment of titanium rods!

The process parameters of laser welding are difficult to grasp, because the thermal efficiency fluctuates greatly during the welding process, and the surface condition of the welded titanium rod has a great influence on the thermal efficiency: the brighter the surface, the larger the emitted laser light, and most of the laser energy is reflected to other objects , In the form of "heat" to the surrounding materials or media. But the thermal efficiency will suddenly change. Before the titanium metal rod is melted, only about 10%-20% of the light energy is absorbed by the astm b348 titanium rod and heats the titanium metal rod. When the temperature rises to the melting point of the weld metal and starts to melt, the light absorption rate of the titanium metal rod increases sharply . The titanium rod company tells you that at this time, about 60%-80% of the light capacity is absorbed by the metal, and the sudden change in the thermal effect can easily cause the weld to burn through.

In order to avoid or reduce this adverse effect, that you can take corresponding measures, such as welding Grade 1 Titanium Bar; roughening the surface, using pulsed laser beams; adjusting the input energy; adjusting the spot size; changing the attenuation wave Pulse width and steepness.

A natural ruby ​​crystal containing aluminum oxide and dissolved in a low concentration of chromium atoms is used as the working material of the laser generator, which is called a solid-state laser generator. If CO2 is used as the working substance of the laser generator, it is called the force gas laser generator.

At present, the power of the laser welding machine is only kilowatts, and the price is expensive, the welding cost is high, and the application range is not wide. It is only used for the solder joints of some small parts in the manufacture of some instruments and meters, especially when some solder joints are hidden and cannot be welded by ordinary welding methods. Multi-station welding can be realized by using laser beam, optical fiber and deflection prism.

Correction process for internal defects of titanium alloy pipes and titanium pipe welds

The internal shortcomings of Titanium Alloy Seamless Rectangular Tube welds, lack of penetration, refers to a defect in which the workpiece and the weld metal or the part between the weld layers are not fused. Incomplete penetration weakens the welding seam working section, constitutes severe stress concentration, greatly reduces the joint strength, and it often becomes the source of weld cracking. There is non-metallic slag in the slag inclusion weld, which is called slag inclusion. The slag inclusion reduces the working section of the weld, and constitutes a stress concentration, which will reduce the strength and impact toughness of the weld.

When the pore weld metal absorbs too much gas (such as H2) or the gas (such as CO) generated by the internal metallurgical reaction of the molten pool at high temperature, it is too late to be discharged when the molten pool is cooled and condensed and is formed inside or on the outside of the weld Holes are pores. The existence of pores reduces the useful working section of the weld and reduces the mechanical strength of the joint. If there are penetrating or continuous pores, it will severely affect the tightness of the weldment. During or after welding, cracks in the metal part of the welded joint area are called cracks. Cracks can occur in the weld, and can also occur in the heat-affected zone on both sides of the weld. Sometimes it occurs on the outside of the metal, and sometimes inside the metal.

Usually, according to the mechanism of crack occurrence, it can be divided into two types: hot crack and cold crack. Thermal cracks occur during the crystallization process from liquid to solid in the weld metal, and most of them occur in the weld metal. The main reason for its occurrence is the presence of low melting point substances (such as FeS, melting point 1193°C) in the weld, which weakens the contact between the grains. When subjected to greater welding stress effects, it simply causes cracks between the grains. . When the weldment and electrode contain a lot of impurities such as S and Cu, thermal cracking simply occurs. Thermal cracks have the characteristic of spreading along the grain boundary. When the crack penetrates the surface and communicates with the outside, it has a significant hydrogenation tendency. Cold cracks occur during the cooling process after welding, mostly on the base metal or the fusion line between the base metal and the weld. The primary reason for this is that the quenching arrangement is formed in the heat-affected zone of the weld. Under the effect of high stress, it causes cracks in the crystal grains. When welding easy-quenchable ASTM B861 25*1.2mm Titanium Tube For Chemical with high carbon content or more alloying elements, The most prone to cold cracks. Too much hydrogen melted into the weld can also cause cold cracks. Cracks are one of the riskiest shortcomings. In addition to reducing the load-bearing section, severe stress accumulation will occur. During use, the cracks will gradually expand and eventually cause damage to the components. Therefore, such shortcomings are usually not allowed in the welding layout.