How to enhance the wear resistance of titanium rods and titanium wires?

The unique properties of titanium make it an excellent material for making bicycle frames. Its high strength, low density, and low modulus of elasticity (the modulus of elasticity can be regarded as an index to measure the difficulty of elastic deformation of the material), excellent Fatigue resistance, and corrosion resistance make the manufactured titanium alloy frame not only very strong and durable but also very light.

Titanium materials will not break, will not rust, and will not corrode in any atmospheric environment. Titanium is so resistant to corrosion that it doesn't even need any paint treatment. We just lightly rub the surface to brighten its natural color, and the titanium color can better reflect the low-key and luxurious texture of this metal.

Titanium has inherent flexibility like steel, but this characteristic of titanium is more obvious. Therefore, it has a very slight elasticity, which means that it can absorb vibrations from the road surface. Before it is transmitted to the rider, (the titanium Seatpost can also eliminate some vibrations) will have a very smooth riding feeling.

Unlike aluminum or carbon bicycle frames, titanium bicycle frames will not break suddenly in an accident. This is because, like steel, it has a certain degree of flexibility. (In fact, titanium is more flexible than steel, which is why it is so famous for its riding quality.) It is more like steel because it has incredible strength, but it is much lighter than steel and less Rusty.

Grade 7 Titanium Rod     Grade 36 Titanium Wire     titanium welded tube     Grade 2 Titanium Tube

Application of titanium rod, titanium wire and titanium plate in electric power industry

1. Aerospace

The major titanium use countries in the aerospace industry are concentrated in Western countries, especially the United States, where 60% of titanium is used in this field. Asian countries, Japan and China all invest about 10% of titanium in this field. However, with the rapid development of Asian aerospace in recent years, the consumption of titanium in the aerospace field will increase accordingly. From a global perspective, the aviation industry plays a decisive role in the titanium market. Historically, the major cycles of the titanium industry are closely related to the aviation industry.

2. Civil aircraft

(1) Reduce structural weight and improve structural efficiency

(2) Meet the use requirements of high temperature parts

(3) Meet the requirements that match the structure of the composite material

(4) Meet the requirements of high corrosion resistance and long life

3. Military weapons

The development and procurement of military weapons continue to develop in the direction of lightness and flexibility. In order to meet the fighter's combat performance requirements, in addition to the use of advanced design technology, it is necessary to use materials with excellent performance and advanced manufacturing technology. One of the important measures is to choose a large number of titanium alloys and improve the application level of advanced titanium alloys.

4. Car

Reducing fuel consumption and reducing hazardous waste (CO2, NOX, etc.) emissions have become one of the main driving forces and directions for technological progress in the automotive industry. Research shows that lightweight is an effective measure to save fuel and reduce pollution. For every 10% reduction in the quality of a car, fuel consumption can be reduced by 8%-10%, and exhaust emissions can be reduced by 10%.

In terms of driving, the acceleration performance of the vehicle is improved after the weight is reduced, and the vehicle control stability, noise, and vibration are also improved. From the perspective of collision safety, after the car is lightweight, the inertia during a collision is small and the braking distance is reduced.

5. Medical industry

Titanium has a wide range of applications in the medical field. Titanium is close to human bones and has good biocompatibility to human tissues without toxic side effects. Human implants are special functional materials closely related to human life and health. Compared with other metal materials, the main advantages of using titanium and titanium alloys are as follows:

1 Light weight; 2 Low modulus of elasticity; 3 Non-magnetic; 4 Non-toxic; 5 Corrosion resistance; 6 High strength and good toughness.

The amount of titanium alloy used in surgical implants is increasing at an annual rate of 5%-7%. Femoral heads, hip joints, humerus, skull, knee joints, elbow joints, shoulder joints, metacarpophalangeal joints, jaws, and cardiac membranes, kidney membranes, vasodilators, splints, prostheses, made of titanium and titanium alloys Hundreds of metal parts, such as fastening screws, have been transplanted into the human body. Good results have been achieved, and they have been highly praised by the medical community.

6. Chemical industry

Titanium has excellent corrosion resistance, mechanical properties and process properties, and is widely used in many sectors of the national economy. Especially in chemical production, titanium is used instead of stainless steel, nickel-based alloys and other rare metals as corrosion-resistant materials. This is of great significance to increase output, improve product quality, extend equipment life, reduce consumption, reduce energy consumption, reduce costs, prevent pollution, improve working conditions, and increase labor productivity.

7. Ocean Engineering

With the development of science and technology and the depletion of land resources, mankind's development and utilization of the ocean has been on the agenda. Titanium has excellent corrosion resistance to seawater, and is widely used in seawater desalination, ships, ocean thermal energy development, and seabed resource exploitation.

8. Daily life

Titanium is widely used in daily life and can be described as ubiquitous. For example, golf heads, bicycle frames, tennis rackets, wheelchairs, spectacle frames, etc. are all used in titanium.

The application of titanium in sporting goods due to its light weight and high strength has gradually expanded from the earliest tennis rackets and badminton rackets to golf heads, clubs and racing cars.

The light weight of titanium is also applied to spectacle frames, and titanium is not easy to be allergic to the skin, and the surface of titanium can have brilliant colors after anodizing, so it has been used in spectacle frames since the early 1980s.

Titanium is considered a rare metal because it is scattered in nature and difficult to extract. But it is relatively rich, ranking tenth among all elements. Titanium ore mainly includes ilmenite and rutile, which are widely distributed in the crust and lithosphere. Titanium is also present in almost all living things, rocks, water bodies and soil.

The Kroll method or Hunter method is required to extract titanium from the main ore. The most common compound of titanium is titanium dioxide, which can be used to make white pigments. Other compounds include titanium tetrachloride (TiCl4) (used as a catalyst and used to make smoke screens as air cover) and titanium trichloride (TiCl3) (used to catalyze the production of polypropylene).

Titanium alloy characteristics:

High strength, the density of titanium alloy is generally about 4.51g/cm3, which is only 60% of steel. The strength of pure titanium is close to the strength of ordinary steel. Some high-strength titanium alloys exceed the strength of many alloy structural steels. Therefore, the specific strength (strength/density) of titanium alloy is much greater than other metal structural materials, and parts and components with high unit strength, good rigidity and light weight can be produced. At present, titanium alloys are used in aircraft engine components, skeletons, skins, fasteners, and landing gear.
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Application of titanium alloy materials such as titanium rod, titanium wire and titanium plate in construction industry

When there is a corrosive medium in the titanium tube heat exchanger, it is suitable to use composite plates and titanium-lined tube plates. Nowadays, large-scale exchangers are mostly made of integral tube sheets with a thickness of 100mm and integral heads of the same thickness. Since the use of titanium is often associated with strong corrosive media, in order to avoid corrosion, in the structural design of titanium equipment, attention should be paid to:

(1) Avoid gaps and stagnant areas. In order to achieve a complete seal and prevent a gap between the tube and the tube sheet, expansion and sealing welding should be adopted. Regardless of whether it is an all-titanium or composite board, many designers support the use of step welding based on the consideration of weld penetration, but some people think that this will cause greater difficulties in repair welding. The fasteners in the tower should be connected by wedges instead of bolts. The sealing surface of the flange should be covered with asbestos gasket with PTFE film. Under the conditions of high temperature, high pressure and strong corrosion, it is recommended to use titanium reinforced polytetrafluoroethylene winding and T0.2Pd metal pad.

(2) In the conductive medium, avoid contact between titanium and other metals as much as possible. In the structure, a third material with a potential between the two can be used as a transition layer (such as by surfacing) or isolated by insulating materials. When the medium is seawater, a heat exchanger made of titanium tubes filled with different metal tube sheets and rolled up can be used. The premise is that the tube sheet material is compatible with titanium.

(3) The expansion coefficient of titanium is smaller than that of steel. Therefore, thermal stress cracking may occur in the heating equipment of the titanium steel composite structure, and the thermal compensation link should be set in the design.

(4) In some corrosive media with high flow rates and sudden changes in flow rate, titanium equipment and components are prone to erosion, so when the flow rate exceeds 6m/s, an anti-scouring baffle should be installed. In the titanium tube heat exchanger, due to vibration, the contact between the titanium tube and the supporting hole is prone to fracture. Therefore, shock absorption measures should be taken and a PTFE ring can be caulked at the contact between the titanium tube and the supporting hole.

(5) The thermal conductivity of the titanium surface depends to a large extent on the design and process parameters. For the heat exchanger using cold water as the coolant, the available value is 425~550W/(m2·℃); for the heat exchanger using steam or hot water to heat the static liquid, the available value is 800~1450W/(m2·℃) . For the condenser cooled by seawater, when the tube wall thickness is 0.5~1.0mm and the flow velocity is lower than 3.9m/s, the measured data is 54006800W/(m2·℃).
machined titanium round bar     3 Inch Titanium Pipe     titanium powder     grade 5 titanium plate

Nuclear submarine made of titanium rod, titanium wire and titanium plate

Among the titanium materials, the most commonly used industrial pure titanium (TA2 is the most widely used), Ti-6Al-4V (when a certain strength is required), and Ti-0.8Ni-0.3Mo (when there are gaps or in a non-oxidizing medium). When hydrogen absorption and hydrogen embrittlement may occur, especially in the case of weld corrosion and hydrogen absorption, low-iron (<0.05%) titanium materials are required. Titanium heat exchangers, condensers, and related auxiliary equipment have been successfully used for more than 20 years in petrochemical enterprises.

There are many products and complicated processes in the petrochemical industry. Here is an example to introduce the application of titanium:

1. Terephthalic acid is the raw material for synthetic polyester, which is prepared by the p-xylene oxidation method in the industry. No matter high-temperature oxidation or low-temperature oxidation, there is high-temperature corrosion of acetic acid and bromide. In the medium with a temperature higher than 135℃, pitting corrosion of 316L stainless steel will occur after dozens of hours. Therefore, the design specification stipulates that titanium must be used above 135°C. Beijing Petrochemical Plant has introduced a complete set of titanium equipment, including 16 oxidation reactors, solvent dehydration towers, heaters, condensers, and reboilers. Nanjing Yangzi Petrochemical Company has introduced an annual output of 450,000 tons of terephthalic acid equipment, 56 sets of titanium equipment, and a large number of titanium pipeline valves. The oxidation reactor introduced by Shanghai Petrochemical Plant is 32m high, with an upper diameter of 4m, a lower diameter of 5.3m, a volume of 505m, and a weight of 175t. The effect of using titanium material is very good, and the prospect of promotion and application is bright.

2. In the device where ethylene is oxidized to acetaldehyde, acetaldehyde is oxidized to acetic acid, and propylene is oxidized to acetone, the main corrosive medium is a catalyst, except that the raw materials and products are corrosive. Stainless steel corrodes quickly, and only titanium has Good corrosion resistance. As early as 1963, the United States successfully applied titanium in the production of acetaldehyde by oxidation of ethylene. my country's first ethylene oxidation to acetaldehyde plant was put into use in 1976, and the titanium plant has been operating well so far. Foreign titanium-lined reactors are as high as 9.6m, with a diameter of 3m, and there are 11 sets of titanium equipment including heat exchangers, catalyst regeneration towers, and acetaldehyde solution coolers. Since the 1980s in my country, Shanghai and Jilin have introduced foreign complete sets of equipment for the production of acetaldehyde by ethylene oxidation. Many of the equipment and pump valves are made of titanium. Compared with stainless steel, it has obvious advantages and the use effect is very satisfactory.

3. Urea is a high-quality fertilizer and a raw material for petrochemicals. Since the first titanium-lined urea synthesis tower was put into production in 1963, there have been nearly 10,000 equipment in operation all over the world, and practice shows that there is no obvious corrosion in the titanium-lined synthesis tower. The converted corrosion rate of 316L stainless steel is 4.1-4.5 mm/a. Therefore, titanium has better economic benefits than stainless steel. In addition to the titanium-lined urea synthesis tower, CO 2 stripping towers, heat exchangers, mixers and pump valves have been used in China since the 1970s.

4. In the refining of crude oil with high sulfur and high salt content, titanium equipment is ideal. In foreign countries, titanium equipment has been successfully used in many processes such as atmospheric distillation equipment, sewage treatment equipment, desulfurization separation tower condenser, and stripping tower radiator for many years. Our country has also used cast titanium seawater pumps, titanium condensers in catalytic cracking fractionation, cryogenic separation titanium condensers, and porous titanium plates in this system, all of which have been in normal operation for more than ten years.

5. Chlorinated hydrocarbon is one of the largest varieties of the petrochemical industry. Due to the chlorination reaction involved, stainless steel equipment has been difficult to handle. In foreign countries, titanium materials have been used to manufacture methylene chloride rectification towers, trichloroethane heat exchangers, condensation towers and fractionation towers, trichloroethylene condensation towers, perchloroethylene heat exchangers, and polychloride coil heaters. In the production of vinyl chloride in my country, the cooling tower, wastewater stripping tower, and wastewater storage tank tray support frame, connection pipe, flange sealing surface, using Ti-0. 2Pd lining has been used for nearly ten years without corrosion. Titanium pipes, joints, and gas distributors have all been made of titanium for many years.

6. Phenol is an important raw material for the petrochemical industry. It is a new process to obtain phenol and acetone from cumene and cumene peroxide using propylene and benzene in oil and gas refining as raw materials. Foreign countries have adopted titanium equipment more than ten years ago, and this technology is still under development in my country. The old process used benzene sulfonated alkali solution to produce phenol. Our country has adopted a titanium neutralization reactor, titanium coil cooler, ion titanium nitride agitator sleeve, and titanium target, and the effect is very good.

7. Oxidation of acetaldehyde to acetic acid is a common technology in our country. Titanium is now used as a high-boiling material reboiler, first-grade acetic acid tower reboiler and condensing cooler and other equipment. Foreign countries have adopted titanium equipment in rectification towers, fractionation towers, and distillation towers. Especially in the oxidation of lower alkane to produce acetic acid, there are many by-products, with a formic acid content of 8%, which is extremely corrosive. At this time, titanium is used to replace stainless steel, and the effect is very ideal.
T40 Titanium Bar     bending titanium tubing     Sputtering Target     Grade 7 Titanium Plate

Mechanical properties of titanium and titanium alloys

The main measure to eliminate cold barriers or flow marks is to use the correct gating system to prevent two or more metal flows from converging, or turbulent and interrupted flow when liquid titanium is filling the mold. In gravity pouring, it is recommended to use bottom pouring system as much as possible, so as to avoid or reduce cold barriers or flow marks on the surface of castings as much as possible.

In order to obtain castings with a smooth surface and a complete filling, centrifugal casting is usually used. At this time, the flow rate of liquid titanium from the bypass into the cavity is very large, which is prone to strong splashing. It is very difficult to completely avoid cold barriers or flow marks. In this case, more attention should be paid to the process design of the castings, reasonable casting process, correct gating system, avoid reverse metal flow in the cavity, try to eliminate metal splash, and try to increase the molten metal if possible. The pouring temperature.

The influence of the wall thickness of titanium castings on the microhardness of the surface layer (the degree of surface contamination). For castings poured in the same mold, the thicker the casting, the more serious the contamination of the surface layer. For castings with wall thickness (greater than 10mm), it is not advisable to preheat the mold to an excessively high temperature before pouring. Some literature pointed out that when the wall thickness of the casting is below 10mm, the influence of the wall thickness of the casting on the surface roughness of the casting is not very obvious. The contamination layer on the surface of the casting is mainly caused by the interaction between titanium and the mold and the adsorption of a gas on the surface of the mold, of which oxygen is the most harmful.
titanium alloy rod     Gr1 Pure Titanium Pipe     Titanium Planar Target     thin titanium sheet

A feasible method for reducing surface contamination of titanium screws and titanium workpieces

Russia is an international leader in the research and manufacturing technology of building titanium alloy nuclear submarines, and is also the first country to build pressure hulls with titanium alloys. During the peak period, the annual output of titanium alloy plates and pipes for submarines was as high as 10,000 tons, accounting for 1/3 to 1/2 of the annual output of titanium alloy processed materials. Titanium plates for submarine heat exchangers require good thermal conductivity. The shell material is required to have good toughness to resist the shock wave caused by the depth charge explosion. The titanium plate (thick plate) for the submarine shell is produced in St. Petersburg, and the ingot is provided by the Upper Salda Metallurgical Production Joint Company. In terms of the development level of the titanium industry and the scale of use of titanium plates and wires in the shipbuilding industry, Russia is far ahead of all other countries in the world. Because Russia is ahead of competitors such as the United States in the field of ship materials research, its scholars have called on the government to formulate a near-term shipbuilding plan to avoid losing the leading position and development potential it has achieved, and at the same time to ensure that the Russian Navy will continue to lead in the 21st century. In other countries.

Since the 1960s, there have been 4 generations of nuclear submarines developed by Russia. The world’s first K162 all-titanium nuclear submarine was launched in December 1968 and has been in operation for more than 30 years. It has been to various oceans and sea areas and has withstood different loads and loads. Environmental assessment, there has never been any accident. Russia built the first "ALFA" class nuclear submarine in 1970, and continued to build 6 ships from the 1970s to the 1980s. Each of them uses titanium rods, titanium wires, and titanium plates about 3000t. The maximum diving depth is 914m, which is light and fast. .

In the 1980s, six "Typhoon" class nuclear submarines with a capacity of 9000t of titanium rods, titanium wires and titanium plates were manufactured. The first "Typhoon" class nuclear submarine was built in 1980 and commissioned in 1984. Its underwater displacement With a speed of 33800t and an underwater speed of about 27 knots, the "Typhoon" class nuclear submarine is the world's largest submarine. It has a double hull structure. The non-pressure hull is made of high-strength and low-magnetic steel, and the pressure hull is made of titanium alloy. It can carry 20 strategic missiles. The launch of the sixth "Typhoon" submarine was at the end of 1989, and the "Typhoon" series of submarines will be decommissioned at the beginning of the 21st century.

The first submarine in the new series of "The God of the North Wind", which was commissioned in 2003, is the "Yuri Dolgoruky". It is a new fourth-generation submarine, and its combat performance should exceed the existing ones of the same level. All submarines. Its underwater displacement is greater than that of the "Detal" class (11740t), but less than the "Typhoon" class (33800t), and the construction cost requires several trillion rubles.

The "Ohio" missile submarine that the United States entered service in 1980 has an underwater speed of 20n mile/h (knots).
titanium alloy bar     Gr1 Pure Titanium Tube     TiN Sputtering Target     thin titanium plate

Chemical properties of titanium materials such as titanium rods and titanium wires

Whether it is the development of the marine economy or the development of the modern navy, it is necessary to develop a series of marine engineering equipment. Practice has shown that advanced offshore equipment, whether it is deep-sea oil and gas exploration equipment, nuclear submarines, deep submersibles and other equipment, are all titanium-related equipment. Lightweight and corrosion-resistant titanium and titanium alloy materials can be used to achieve high-efficiency offshore equipment. , Long life and high reliability make a major contribution.

At present, the time is ripe to accelerate the development of titanium for marine engineering. my country is already a big country in the world's titanium industry. It has a relatively complete titanium R&D-production-application system, large-scale production capacity and many application technology reserves. It is not only necessary but also feasible to accelerate the development of titanium for marine engineering. Compared with commonly used materials such as steel, stainless steel, copper and aluminum, the most prominent features of titanium are low density, high specific strength, and strong corrosion resistance. At the same time, it is also resistant to seawater erosion, non-magnetic, non-cold brittleness, and high sound permeability. The coefficients and other properties are convenient for forming, casting, and welding, making it widely applicable to various marine engineering.

Titanium can be used in ocean engineering, but there are also some shortcomings and problems worth noting. Titanium alloy materials for marine engineering face many challenges, mainly in five aspects:

1. Titanium production

Due to the high melting point of titanium (1668°C), high resistance to high temperature deformation, and narrow thermal processing temperature zone, it is difficult to produce titanium materials, especially large-size, high-performance titanium materials. Not only a large vacuum melting furnace (vacuum electric arc furnace, electron beam cooling bed furnace, etc.) is required, but also heavy pressure processing equipment (forging press, rolling mill, extruder, etc.) is required. Titanium production unit product investment is huge, up to 300,000 ~ 400,000/ton. The equipment capacity of titanium production is equal to or greater than that of steel of the same specification, and its output and equipment utilization are only a few tenths of it, resulting in high production costs.

2. Product design

Titanium has a high flex-strength ratio (above 0.9), a high welding strength coefficient (above 0.9), and a low modulus of elasticity, thermal conductivity and damping coefficient. Under certain conditions, titanium will have crevice corrosion, contact galvanic corrosion and hydrogen embrittlement. Due to these physical, chemical and mechanical characteristics of titanium, the design of titanium equipment is required to adopt new design specifications and technical specifications (such as safety factor, corrosion margin, fire and explosion prevention measures, structural form, weld form, etc.). Titanium materials have a small damping coefficient (except for TiNi shape memory alloys), and they will vibrate during use. Therefore, anti-vibration and vibration reduction measures must be taken. Titanium has only a few decades of history in the industrial field, there is little design experience, and many issues remain to be explored.

3. Product manufacturing　　

Due to the low modulus of elasticity of titanium, large springback during cold working, low thermal conductivity, easy abrasion and scratches on the surface, etc., it brings certain difficulties to the molding, heat treatment, and machining of titanium parts. Mature technology It takes a long time to explore.

4. Titanium material application

Due to the strong corrosion resistance of titanium, many titanium equipment are "permanent" or semi-permanent equipment, and the equipment assessment cycle is very long, so that the first, second, and third generation engineers and technicians of the equipment user can not fully grasp the application history data of a certain equipment , It is impossible to make a comprehensive and objective evaluation of the use effect of titanium equipment.

5. Material selection concept

It is still difficult for most people to break through the inertial thinking that "titanium is too expensive". In the case of limited investment capacity, it is difficult to use titanium, which is 5-10 times more expensive than hull steel, to replace steel or copper to manufacture offshore equipment. Relatively speaking, the one-time investment of titanium equipment is indeed very large, and the technical and economic advantages of titanium equipment are mainly reflected by the "full life cost", that is, mainly by long-term benefits. Titanium should be expanded in marine engineering, and a lot of work must be done in benefit evaluation and publicity.
titanium hexagon rod     Gr12 Ti-0.3Mo-0.8Ni Titanium Plate     titanium metric screw     F3 Pure Titanium Forging