Thursday, November 19, 2020

The appearance of the titanium rod is very similar to that of steel, with a density of 4.51 g/cm3 and less than 60% of steel, which is the lowest density metal element in refractory metals.

The reaction of titanium alloy materials in the air, such as titanium rods, titanium tubes, etc., is usually related to the three non-metallic elements of oxygen, nitrogen and hydrogen. Their reaction process is closely related to temperature.
Titanium reacts very slowly with oxygen in the air below 100 degrees, and only the surface is oxidized at 500 degrees. As the temperature increases, the surface oxide film begins to dissolve in the titanium, and oxygen begins to diffuse into the metal. However, at 700°C, oxygen does not enter the inner lattice of the metal. When the temperature exceeds 700°C, the diffusion of oxygen to the metal is accelerated, and the surface oxide film loses its protective effect at high temperatures.
The reaction of titanium with oxygen depends on the shape and temperature of titanium. Powder titanium will burn or explode violently under the action of static electricity, sparks and friction in the air at room temperature. However, dense titanium is stable in air at room temperature. When the dense titanium is heated in air, it starts to react with oxygen. First, oxygen enters the crystal lattice on the titanium surface to form a dense oxide film. The oxide film on the surface can prevent oxygen from diffusing into the interior and has a protective effect. Therefore, titanium is stable in the air below 500°C. The color of the surface oxide film is related to the formation temperature. Below 200 degrees is silvery white, 300 degrees is light yellow, 400 degrees is golden yellow, 500 degrees is blue, 600 degrees is purple, 700-800 degrees is red-gray, and 800-900 degrees is gray. In pure oxygen, the initial temperature ratio of titanium to oxygen is lower than the initial temperature ratio in air. At about 500-600°C, titanium burns in oxygen.
Titanium does not react with nitrogen at room temperature, but at high temperatures, titanium is one of the few metal elements that can burn in nitrogen. When the combustion temperature of titanium in nitrogen is higher than 800°C, the reaction between titanium and nitrogen is very violent. The reaction of titanium and nitrogen can not only generate titanium nitride (ti3n, Ti N, etc.), but also form a Ti-N solid solution. When the temperature is 500-550℃, titanium starts to absorb nitrogen and form interstitial solid solution; when the temperature exceeds 600℃, the nitrogen absorption rate of titanium increases. In the Ti-N solid solution, nitrogen enters the titanium lattice in the form of titanium nitride, the phase transition temperature of titanium increases, and nitrogen is also a stabilizer of titanium. The solubility (mass fraction) of nitrogen in air is 7% at 1050°C and 2% at 2020°C. However, the absorption rate of nitrogen by titanium is much slower than the absorption rate of oxygen. Therefore, titanium mainly absorbs oxygen in the air, while the absorption of nitrogen is secondary.

Tuesday, November 17, 2020

Progress in the application of titanium alloy precision thermoforming technology in aerospace

Because titanium has excellent corrosion resistance, mechanical properties and process properties, it is widely used in many sectors of the National Economy. Especially in chemical production, the use of titanium instead of stainless steel, nickel-based alloys and other rare metals as corrosion-resistant materials can increase production, improve product quality, extend equipment life, reduce consumption, reduce energy consumption, reduce costs, and prevent Pollution, improvement of working conditions and productivity are all very important. In recent years, the scope of titanium used in the chemical industry in our country has been expanding, and the amount used has increased year by year. Titanium has become one of the main anti-corrosion materials in chemical equipment. Titanium, as a corrosion-resistant structural material used in chemical equipment, has established its position, and as an ideal material in chemical equipment, titanium has increasingly attracted the attention of engineers and technicians.
(1) Chlor-alkali industry
The Chlor-alkali industry is an important basic raw material industry, and its production and development have a great impact on the national economy. This is because the corrosion resistance of titanium to chloride ions is better than that of commonly used stainless steel and other non-ferrous metals. Currently, titanium is widely used in the Chlor-alkali industry to manufacture metal anode electrolyzers, ion-exchange membrane electrolyzers, wet chlorine coolers, refined brine preheaters, dechlorination towers, chlorine cooling scrubbers, etc. In the past, the main components of these equipment used non-metallic materials (such as graphite, polyvinyl chloride, etc.). The mechanical properties, thermal stability and processing performance of non-metallic materials were not ideal, resulting in bulky equipment, high energy consumption, and longevity. Short, and affect product quality and pollute the environment.
(2) Soda ash industry
Soda ash is one of the most basic chemical raw materials, and it is directly related to the development of the national economy. During the production of soda ash, the gaseous media are mostly NH3 and CO2, and the liquid media are mostly NaC1, NH4C1, NH4HCO3 and solutions with a higher concentration of C1-. Carbonization tower small tubes and hot mother liquor coolers are used for carbonation reaction with carbon drink and cast iron The main equipment such as coolers, crystal external coolers, etc., are not corrosion-resistant, with serious corrosion and leakage, and their service life is less than three years.
Titanium and its alloys have many excellent characteristics such as lightweight, high strength, strong heat resistance, and corrosion resistance. They are known as the "future metal" and are new structural materials with promising development. Titanium and its alloys not only have very important applications in the aviation and aerospace industries, but also have begun to be widely used in many industrial sectors such as chemical industry, petroleum, light industry, metallurgy, and power generation.

Monday, November 16, 2020

Cleaning of titanium pipe welding and oxide film removal of welding groove:

Titanium is a very special metal. It is very light in texture, yet very tough and corrosion-resistant. It retains its own color for life at room temperature. The melting point of titanium is similar to that of platinum, so it is often used in aerospace and military precision parts. After adding electric current and chemical treatment, different colors will be produced. Titanium has excellent resistance to acid and alkali corrosion. Titanium that has been immersed in "aqua regia" for several years is still bright and radiant. If titanium is added to stainless steel, only about one percent is added, which greatly improves the ability to resist rust.
Titanium has excellent characteristics such as low density, high temperature resistance, and corrosion resistance. The density of titanium alloy is half that of steel and the strength is almost the same as that of steel; titanium is resistant to high temperatures and low temperatures. It can maintain high strength in a wide temperature range of -253℃~500℃. Metal processing WeChat, the content is good and worthy of attention. These advantages are necessary for space metal. Titanium alloy is a good material for making rocket engine shells, artificial satellites, and spacecraft. It is called "space metal". Because of these advantages, titanium has become a prominent rare metal since the 1950s.

Thursday, November 12, 2020

What is the application of titanium plates in the medical industry?

The aerospace industry has high requirements for the weight, strength, resistance, and corrosion resistance of materials. Titanium alloys perfectly meet the requirements of aerospace materials. Titanium alloy is the main construction material of aircraft and is widely used in various parts such as aircraft landing gear, the outer structure of the fuselage, engine turbine blades, casing and so on. Under the conditions of the country's "independent and controllable" requirements for military products and the continuous development of civil aviation, the demand for titanium alloys will continue to rise, and China's titanium alloy industry has a bright development prospect.
In the statistics on the number of global military aircraft at the end of 2019, China ranked third, second only to the United States and Russia, which once again shows that the domestic aerospace titanium material market has great potential.

Tuesday, November 10, 2020

Titanium and titanium alloy high-end products have greater future development potential

There are more than 160 titanium alloy manufacturers in my country, and the number of companies with better independent research and development capabilities, higher product technology content, and better brand characteristics is relatively small. Most of them are concentrated in the low-end and mid-end areas, especially the low-end market with excess capacity. The competition is fierce. my country's petrochemical, aerospace, power, marine engineering and other industries continue to have strong demand for high-end titanium alloy products, and the market demand for titanium alloys is shifting from the low-end to mid-to-high-end. However, the number of high-end titanium alloy manufacturers in my country is relatively small and the market supply is insufficient.
At this stage, only 10% of my country's titanium alloy products are used in high-end areas, while 50% of US titanium alloy products are used in high-end areas. Compared with developed countries, my country's titanium alloy industry has a large gap. As my country's large aircraft manufacturing gradually increases and military aircraft continue to upgrade, the aviation industry's demand for titanium alloys will continue to increase. From the perspective of the import unit price of my country's titanium alloy products in 2018, the import unit price is much higher than the export unit price, indicating that the supply of high-end titanium alloy products in my country is insufficient and the market depends on imports. The industry needs to continuously improve R&D and innovation capabilities, improve product performance, develop new functional products, and accelerate the pace of import substitution in the high-end titanium alloy market.
In 2017, my country's titanium output was around 33 million tons, and the industry output declined in 2018. Affected by factors such as weakening market demand, high port inventory, and unoptimistic economic conditions, in 2018, large enterprises in my country's titanium alloy industry had a good operating rate, small enterprises were cautious in resuming production, and the overall output of the industry fell. As the demand for my country's high-end titanium alloy market grows, large-scale enterprises with higher technological levels have greater potential for future development.
According to industry analysts, the national policy attaches more importance to the high-tech industry. The domestic aerospace, shipbuilding, marine engineering, transportation, military and other fields have a growing demand for high-end materials. The production strategy of high-end titanium alloys is of great significance. It has become an inevitable trend for the industry to adjust its product structure and shift to high-end areas. Therefore, the titanium alloy industry will have higher and higher technical requirements for production enterprises, and enterprises can only achieve further development by continuously improving their core competitiveness. In the future, the technical barriers to entry into the titanium alloy industry will continue to increase.

Sunday, November 8, 2020

Brief Analysis of the Status of Titanium Industry in China

The scale of titanium is one of the basic knowledge of titanium. The scale of titanium generally refers to the length of titanium. The length of titanium mainly includes length, width, height, diameter, radius, inner diameter, outer diameter, and wall thickness. The unit of the length of titanium material is the meter (m), centimetre (cm), millimeter (mm) and so on. To know that they have to understand titanium, titanium includes titanium rods, titanium plates, titanium tubes, titanium wires, etc., which are rolled from titanium and titanium alloys.
1. The scale of titanium
It is a useful way to save data. The expert scale of titanium rods means that the length or length by width is not less than a certain scale or the length of the titanium plate. Delivered within the scale of the length and the width. The production unit can produce and supply according to this standard demand.
2. Indefinite
Refers to the general length, where the product scale (length or width) is within the scale of the specification and does not require a fixed scale. Indefinite length is also known as general length (through ruler). For metal materials that are delivered according to an indefinite length, they can be delivered within a regular length scale. For example, for the general round titanium of no more than 25mm, the general length rule is 4-10m, and the round titanium with the length within this scale can be delivered.
3. Fixed length
Cut to a fixed size according to the order requirement is called fixed-length. When delivering according to the fixed-length length, the metal materials submitted must have the length specified by the purchaser in the order contract. For example, if the contract states that the delivery is based on a fixed length of 5m, the delivered materials must be 5m long. Anything shorter than 5m or better than 5m is unqualified. But in fact, it is impossible for the delivery to be all 5m long, so the rule allows for a positive error, but not a negative error.
4. Times the ruler
The one that is cut into integer multiples according to the fixed scale required by the order is called the double ruler. When delivering the goods in multiple lengths, the length of the metal materials submitted must be an integer multiple of the length specified in the purchase contract (called a single length) (with a saw cut). For example, the buyer of a titanium rod manufacturer requires a single ruler length of 2m in the order contract, then the length is 4m when cut into a double ruler, and 6m when cut into a triple ruler, and one or two are added separately. A saw cut. The amount of saw cut has rules in the specification. When the double ruler is delivered, only positive errors are allowed, and negative deviations are not allowed.
5. Narrow ruler
The width is less than the lower limit of the indefinite width of the standard rule, but not less than the narrowest width promised. When delivering the goods according to the narrow rule, it is necessary to pay attention to the narrow rule share and the narrowest rule of the relevant regulations.
6. Short feet
The length is less than the lower limit of the indefinite length of the titanium pipe specification rules, but not less than the shortest length allowed is called short length. For example, the rules in the specification for water and gas transportation of titanium pipes allow 10% (according to the number of pieces) of short-length titanium pipes of 2-4m in each batch. 4m is the lower limit of indefinite length, and the minimum length allowed is 2m.

Thursday, November 5, 2020

Advantages of titanium alloy pipe

TC4 titanium alloy has a series of advantages such as excellent corrosion resistance, low density, high specific strength, better toughness and weldability, etc., and has been successfully applied in the aerospace, petrochemical, shipbuilding, automotive and pharmaceutical sectors. During the hot forming process of TC4 titanium alloy, a layer of oxide scale will be formed on the surface, and the color of the obtained oxide scale will be different at different hot forming temperatures. Among them, when the thermoforming temperature is about 600°C, the oxide scale is blue; when the thermoforming temperature is about 850°C, the oxide scale is gray to reddish; and when the thermoforming temperature is 900°C, the oxide scale is gray. With the increase of temperature, the difficulty of removing oxide scale gradually increases. The removal of titanium alloy scale at home and abroad mostly adopts a two-step method, that is, first molten alkali washing and then acid washing; however, the temperature of molten alkali washing medium is higher, which can reach about 450℃, and it is easy to cause semi-finished products of α+β and β titanium alloy The premature aging strengthening of sulphate brings difficulties to further processing. In addition, washing with nitric acid and hydrofluoric acid after hot alkaline washing may also cause hydrogen embrittlement corrosion on the surface of the titanium alloy.
The researchers studied the process of removing the oxide layer on the surface of the oxide scale obtained at the three temperatures of 590, 850, and 920°C by first washing with a low-temperature alkaline solution and then pickling.
The lye used in the test is a mixed supersaturated solution of industrial pure NaOH and industrial pure NaNO2, and a mixed solution of hydrofluoric acid and nitric acid (volume ratio HF:HNO3:H2O=1:1:3) is used for pickling. The TC4 titanium alloy that has been washed with hot alkali and washed with water is completely immersed in the acid solution for 20 seconds and then taken out, and then washed with tap water. Finally, the aforesaid sample was cleaned by acetone or alcohol ultrasonic wave and then dried and weighed. The mass of the sample before and after hot alkaline washing and acid washing was measured with an electronic balance, with an accuracy of 0.001g. The analysis shows that the oxide scale on the surface of the TC4 titanium alloy can be completely removed by the process of hot alkaline washing and then acid washing. conclusion as below:
(1) The thickness of TC4 titanium alloy hot forming surface oxide scale is less than 2μm.
(2) Through the hot alkaline washing and pickling process, the oxide scale on the surface of the TC4 titanium alloy can be completely removed. The lye ratio is 700g/L NaOH+250g/L NaNO2, and the boiling temperature is about 160℃. Soaking for 6h can achieve the removal effect.
(3) The hydrogen mass fraction of TC4 titanium alloy with an oxide scale does not change much through the hot alkaline washing and pickling process, which meets the production needs.

Tuesday, November 3, 2020

Processing characteristics of titanium alloy pipe

1. Crevice corrosion: Titanium rod manufacturers pointed out that crevice corrosion is a local corrosion phenomenon that occurs in close gaps, which can be caused by structures (such as flange connection surface or gasket surface, tube and tube sheet expansion joint, and The connecting surface of bolts or rivets, etc.) can also be caused by scaling or deposits under the covering surface. In the early days, it was believed that titanium did not undergo crevice corrosion at all in seawater and salt spray. Later, in high-temperature chloride medium (such as seawater heat exchanger), wet chlorine gas (such as wet chlorine gas tube condenser), oxidant corrosion inhibition hydrochloric acid solution In media such as formic acid and oxalic acid solutions, crevice corrosion damage of equipment has occurred successively.
Crevice corrosion of titanium rods is related to many factors such as ambient temperature, chloride type and concentration, pH value, and the size and geometry of the crevice. In addition, the crevices composed of titanium and polytetrafluoroethylene, titanium and asbestos and other non-metals are more sensitive to crevice corrosion than those composed of titanium and titanium.
2. Pitting corrosion: Pitting corrosion is a form of corrosion peculiar to passivated metals. Compared with stainless steel or aluminum alloy, the pitting corrosion resistance of titanium is very good. Due to the increasing application of titanium in high-temperature concentrated chloride solutions, the number of pitting corrosion cases of titanium equipment has gradually increased.
The titanium anode basket in electrolytic zinc, the titanium coil heated in zinc chloride solution, and the titanium ball valve of 72% calcium chloride solution at 175℃ have all experienced pitting damage. Generally speaking, pitting corrosion of titanium is more difficult than crevice corrosion, which usually occurs in the form of pitting corrosion on the crevice surface.
3. Galvanic corrosion: Galvanic corrosion is a phenomenon in which dissimilar metals contact (including electrical contact) in the electrolyte solution. Due to the difference in the steady-state potential of the metal, one metal accelerates the corrosion of another metal (ie, anode dissolution). The oxide film is very stable, and it is always in the cathode state. Galvanic corrosion will not accelerate the anode dissolution of titanium.
However, titanium rod manufacturers believe that it is necessary to pay attention to the hydrogen absorption of titanium in the cathode state and ultimately lead to hydrogen embrittlement, and it is necessary to prevent the accelerated corrosion of coupling metals (such as aluminum, copper, zinc, etc.). The size of the galvanic corrosion of the metal depends on the difference of the galvanic sequence of the coupled metal in the medium.

Sunday, November 1, 2020

The role of titanium plate in seawater purification

The environment for repair welding of titanium pipes must not have flowing air. Other aspects are the same as repair welding in the welding box. But pay special attention to:
1. The repair welding area should not be too large, the nitrogen flow during repair welding should be larger, and the gas cannot be stopped in the middle;
2. After the repair welding is completed, nitrogen protection should be continued until the area is cooled;
3. For some special castings, such as complex thin-walled castings, in order to prevent the back surface of the repair welding area from being oxidized, argon gas can be blown on the backside until the casting is cooled;
Fourth, repair welding operators are required to have a higher technical level.

Monday, October 26, 2020

Can titanium alloy be used as jewelry?

Titanium alloy plates and titanium plates are mainly used to manufacture various containers, reactors, heat exchangers, distillation towers, pipes, pumps and valves in the petrochemical machinery manufacturing industry. Titanium can be used as a titanium cathode and condenser in power stations, as well as environmental pollution control devices. The hardness of steel is higher than that of titanium plate, but the specific strength or tensile strength of titanium alloy is higher than that of high-quality steel. Titanium alloy has good heat resistance, low-temperature toughness and fracture toughness, so it is mostly used as aircraft engine parts and rocket and missile structural parts. Titanium alloy can also be used as fuel and oxidant storage tanks and high-pressure vessels. There are already automatic rifles, mortar seat plates and recoilless gun launch tubes made of titanium alloy.
1. Memory function
Titanium-nickel alloy has one-way, two-way and omnidirectional memory effects at a certain ambient temperature, and is recognized as the best memory titanium alloy. Pipe joints are used in engineering for the hydraulic system of fighter jets; the oil pipeline system of a petroleum joint enterprise; a parabolic mesh antenna with a diameter of 500mm made of 0.5mm wire is used on aerospace vehicles; used in medical engineering to make snoring Treatment; Titanium plates are made into screws for fracture healing. The above applications have achieved obvious results.
2. Superconducting function
The niobium-titanium plate exhibits a zero-resistance superconducting function when the temperature is lower than the critical temperature.
3. Hydrogen storage function
Titanium-iron alloy has the property of absorbing hydrogen, which can store a large amount of hydrogen safely, and release hydrogen in a certain environment. This is very promising in hydrogen separation, hydrogen purification, hydrogen storage and transportation, and the manufacture of heat pumps and batteries that use hydrogen as energy.
Titanium dioxide, the oxide of the titanium plate, is a white powder and a better white pigment, commonly known as titanium white. In the past, the main purpose of mining titanium ore was to obtain titanium dioxide. Titanium white has strong adhesion, is not easy to undergo chemical changes, and is always white. Especially valuable is that titanium dioxide is non-toxic. It has a high melting point and is used to make refractory glass, glaze, enamel, clay, high-temperature resistant laboratory utensils, etc.

Friday, October 23, 2020

Characteristics of titanium plate

The rolling process of titanium alloy bars is mainly by cooling the forging bar stock of larger specifications after rolling. The cooled bar mainly takes the form of needles, thin flakes or coarse flakes. Titanium alloy rolled billets can have strong toughness and tensile properties after rolling and cooling, but the titanium alloy bars at this time do not have the characteristics of high strength and high plasticity. Generally, industrial production requires the processing of titanium alloy bars to form an equiaxed structure with strong tensile and fatigue properties. However, in the actual rolling process, because the billet is cooled at room temperature, the comprehensive performance of the flake structure is restricted, and only through targeted deformation treatment can it be shafted, which is suitable for market demand. Therefore, the axisization of titanium alloy bar billets during the rolling process is an important issue. If the rolling deformation is large, it is easier to improve the structural variability and mechanical properties. When the deformation is small, it will affect the plasticity and strength of the titanium alloy. At the same time, in the rolling process of titanium alloy bars, it is necessary to perform multiple annealing. In this case, the surface temperature of the rolled piece will be rapidly reduced. Bad hair, and easily cause surface cracks. Therefore, the rolling temperature must be properly controlled. The pass becomes a rolling space for temperature control and continuous deformation. Only by recrystallizing a large number of twins can the comprehensive properties of titanium alloy bars be effectively improved.

Wednesday, October 21, 2020

Titanium plate manufacturing process

Ti55531 alloy is a new type of high-strength and high-toughness β-type alloy with a nominal composition of Ti-5AI-5V-5Mo-3Cr-1Zr. The alloy has good hardenability and a wide range of processing technology and is particularly suitable for manufacturing parts that must withstand huge stress. It is more suitable for connecting devices between structural parts and landing gear, wings, and engine pylons. It is increasingly popular in the aerospace industry and is now used on A380 Airbus aircraft. Compared with the traditional near-beta alloy Ti-1023, the alloy has low smelting and processing costs, does not produce obvious component segregation, and has the advantages of excellent strength and high fracture strength, and gradually replaces Ti-1023.
At present, there have been many studies on the heat treatment process of the alloy bars, but the heat treatment of the plates has not been studied yet. The orthogonal test method is used to optimize the heat treatment process of the alloy plate, and the best heat treatment process is determined, which provides a basis for the production of the plate.

Sunday, October 18, 2020

Design and development of Ti2448 titanium alloy

Titanium alloys can be roughly divided into low-strength titanium alloys, ordinary 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 alloys. Other titanium alloys used for structural parts are called structural titanium alloys.
2. Ordinary strength titanium alloy (~500MPa), mainly including industrial pure titanium, Ti-2AL-1.5Mn (TCl) and Ti-3AL-2. 5V (TA18) is a widely used titanium alloy. Due to its high cost performance and good weldability, it is used to manufacture various aviation sheet parts and hydraulic pipes. It is also often seen in civilian products such as bicycles.
3. Medium-strength titanium alloy (~900MPa), typically Ti-6AI-4V (TC4) titanium alloy, which is widely used in aerospace and other industrial fields.
4. High-strength titanium alloy, whose tensile strength at room temperature is above 1100Mpa, is composed of nearly β titanium alloy and metastable β titanium alloy, and is mainly used to replace the commonly used high-degree structural steel in aircraft structures. Its typical alloys There is Ti-13V-11Cr-3AI. Ti-15V-3Cr-3Sn (TB5), Ti-10V-2Fe-3AI.
Titanium alloys of different strengths are very different in terms of price and performance. During the selection process, customers need to choose the appropriate strength titanium alloy according to the actual use environment.

Tuesday, October 13, 2020

The application of titanium rods on watches

When the world began to produce titanium tube parts, it once encountered a lot of problems. They are mainly metalworkers and technicians who are familiar with aluminum tube parts, but they are not very comfortable with titanium tube forming. First of all, the cutting and trimming process is too fast because the blades of the scissors wear out too quickly. When the shape is adjusted, the hammerhead is very easy to be arrogant. During the knocking process, the clock rebounds very high. Stick to the model. Because of this, everyone refers to titanium as a difficult-to-form material, and industry personnel call it a hot forming material. This is a more general and perceptual evaluation of the forming performance of titanium tubes. But this can't affect people's specific analysis, after understanding its characteristics, in order to make appropriate treatment.
To be precise, titanium not only has the disadvantages of particularly large spring back, but also has significant advantages. For example, in 1970, in the room temperature technical depth test of pure titanium pipes, it successfully processed cylindrical parts with a limit drawing coefficient of 2.75. , Which greatly exceeds the record of heavy materials such as steel, steel and aluminum. Tests carried out as early as 10 years ago have achieved better results, and also used conventional drawing models and other materials to process spherical parts with a height exceeding the radius in a single process. It laid the foundation for the development of our current titanium industry.
Ships will definitely be corroded in seawater, seriously affecting their life span. Then improving the corrosion resistance of the hull has become the first goal of many shipbuilding companies. So what should I choose? If the flow velocity in the cooling water pipe of the hull is relatively high and needs to withstand strong impact and corrosion, titanium pipes should be selected for comparison.

Sunday, October 11, 2020

Drawing process of titanium rod and titanium wire

Titanium alloy screws are not a high-strength material. It has high specific strength. The density of titanium alloy screws is about 50% to 60% of that of 45# steel, but the strength is equivalent. Titanium alloy screws not only have high strength but also have good heat resistance and low-temperature resistance. Titanium has good corrosion resistance to salt, seawater and nitric acid. It is a well-deserved space and ocean metal.
The development trend of my country's titanium industry is very fierce, and it has become a major country in the development of titanium production. The overall output of titanium screw products in my country has shown an increasing trend year by year, and titanium alloy screw materials are also widely used in machinery and equipment, electronic equipment, communication equipment, hardware lighting, construction bridges and other industries, and gradually entered the civilian field. Products usually made of materials are almost used to take advantage of the low density of titanium screws, usually in places where density requirements and weight requirements are combined.
Regarding the phenomenon of titanium screw sliding wire, we sometimes encounter the situation of titanium alloy screw overflow buckle, also called sliding wire. Commonly used on bicycles are the threaded holes of aluminum parts such as stems, cranks, and rod clamps. Titanium screws It's as good as a pedal axle. The perfect repair method is to ream and tap the titanium screw sleeve, but this process is troublesome and costly. In some places, the size is not rich and cannot be reamed. If you encounter a titanium screw thread overflow buckle, cut a short coil spring, fold the head, put it in the screw hole of the overflow buckle, and screw the titanium alloy screw directly into it. Basically, the original aluminum screw hole can be restored. Tight torque, and can be repeatedly disassembled and assembled, and the reed will not fall out. When screwing, you can choose different width coil springs according to the size of the titanium alloy screw hole, or put two coil springs into the titanium alloy screw hole. The possible ways to do it include wrapping a hemp knife, raw material tape, dispensing thread glue or 502, but the result is that the thread cannot be tightened and it is useless. Now introduce a simple repair method. Useless small measuring tapes, easy pull buckles and the like at home, as long as they are retractable, there must be a coil spring inside. Remove the coil spring for use before throwing it away.

Friday, October 9, 2020

Application of medical titanium alloy in the field of dental implants

When the hydrogen content in the titanium pipe is too much, the impact toughness and notched tensile strength will drop sharply due to the brittleness, so it is generally stipulated that the hydrogen content in the titanium pipe should not exceed 0.015%. In order to reduce the amount of hydrogen absorption, fingerprints, rolling mill marks, grease and other residues should be removed before heat treatment. There is no moisture in the heat treatment furnace. If the hydrogen content of the titanium pipe exceeds the allowable value, it must be removed by vacuum annealing.
When the temperature does not exceed 540 degrees, the oxide film of the titanium pipe fittings will not be significantly thickened, and at higher heat treatment temperatures, the oxidation rate will rapidly increase, and at the same time, the internal diffusion layer of the oxide material will become a pollution layer. The high brittleness ratio of the oxygen contamination layer causes cracks and damage on the surface of the part. There are mechanical processing methods for the deoxygenated pollution layer or chemical methods such as pickling and chemical milling. During the heat treatment, the heating time should be as short as possible under the premise of ensuring heat treatment. It can also be carried out in a vacuum furnace or an inert gas heating furnace. . The pollution caused by the titanium pipe fittings being heated in the air furnace should be appropriately avoided or reduced.

Sunday, September 27, 2020

Titanium alloy is an ideal armor material

The density of titanium alloy is small, the inertia of titanium liquid is small, and the fluidity of titanium liquid is poor, resulting in low casting flow. The temperature difference between the casting temperature and the mold is large, and the cooling rate is fast. The casting is carried out under a protective atmosphere. There are inevitably defects such as pores on the surface and inside of the casting, which have a great impact on the quality of the titanium casting. The following describes the surface treatment methods of titanium alloy parts processing.
1. Removal of the surface reaction layer
The surface reaction layer is the main factor affecting the physical and chemical properties of titanium castings. Before the titanium casting is ground and polished, the surface contamination layer must be thoroughly removed to achieve a satisfactory polishing effect. Pickling after sandblasting can completely remove the surface reaction layer of titanium.
Pickling: Pickling can quickly and completely remove the surface reaction layer, and the surface is not contaminated by other elements. The Hf-hcl system and Hf-hno3 system can be used for pickling titanic acid, but the Hf-hcl system has a large hydrogen absorption capacity, while the Hf-hno3 system has a small hydrogen absorption capacity. The hno3 concentration can be controlled to reduce the hydrogen absorption capacity and the surface can be brightened. . In general, the concentration of HF is about 3% to 5%, and the concentration of HNO3 is about 15% to 30%.
2. Treatment of casting defects
Internal pores and internal defects of the shrinkage cavity: Hot isostatic pressure can be eliminated, but it will affect the accuracy of the denture. X-ray flaw detection is used to remove exposed pores on the surface, and laser repair welding has a better effect. Surface pores can be repaired by laser welding.
Three, polishing
1. Mechanical grinding: Titanium has the characteristics of high chemical reactivity, low thermal conductivity, high viscosity, low mechanical grinding ratio, and easy reaction of abrasive tools. Ordinary abrasives are not suitable for grinding and polishing titanium. You can use super-hard abrasives with good thermal conductivity, such as diamond, cubic boron nitride, etc., and the polishing linear speed is generally 900-1800m/min, otherwise, the titanium surface is prone to grinding burns and micro-cracks.
2. Chemical polishing: Chemical polishing is the purpose of leveling and polishing through the oxidation-reduction reaction of metal in a chemical medium. The advantage is that chemical polishing has nothing to do with metal hardness, polishing area and structure shape. All parts in contact with the polishing liquid are polished without special complicated equipment.

Friday, September 25, 2020

Precautions for processing titanium alloy parts during processing

Titanium is stable in the air; because titanium has a low density and a high specific strength, the density is only 0.6 that of steel. The strength of pure titanium is almost the same as that of steel, and the alloy strength is nearly twice that of steel. It has excellent high-temperature resistance, low-temperature resistance, and corrosion resistance. characteristic. Titanium is called "space metal". It can maintain high strength and mechanical properties in a wide temperature range of -253℃~500℃. Since the 1950s, the proportion of titanium in aerospace has increased. The larger, titanium alloy is an important material for making rocket engine shells, artificial satellites, and spacecraft.
Titanium maintains its own color tone for life at room temperature, and its unique silver-gray tone is high polished and mercerized. Matte has a very good performance. It is the most suitable jewelry metal except platinum and gold. It is often used in modern foreign jewelry designs. However, due to the high technical requirements for titanium processing, it is difficult to cast it with ordinary equipment, and it is difficult to weld it with ordinary tools, so it is difficult to form a production scale. Titanium is light but extremely strong. It is an internationally popular jewelry material. In terms of design, its minimalist and clean cut, high design and low-key avant-garde style are highly respected by young white-collar workers.
TC4 titanium rod is a special metal. It has low density, light weight, high specific strength, and strong corrosion resistance. It will not turn black like silver, and will maintain its silvery white tone for life at room temperature. TC4 titanium rods and TC4 titanium forgings are often used in aerospace. Military precision parts. In terms of chemical reaction, the strong corrosive "Aqua regia" can swallow silver and gold, and even erode the so-called "stainless" stainless steel. However, the "Aqua regia" has nothing to do with titanium. ! Stainless steel is also added with titanium metal to achieve acid and alkali resistance.
Titanium plate has a unique purpose in medical doctors. When titanium metal comes into contact with substances, there will be no chemical reaction. In other words, because of the high corrosion resistance and stability of titanium, it will not affect its essence after long-term contact with people, so it will not cause human allergies. It is the only one that has no effect on human autonomic nerves and taste. metal. Titanium is also called "biophilic metal". In the bone damage, fix it with a titanium splint and a titanium bone nail. After a few months, the bone will grow on the titanium splint and the thread of the titanium bone nail, and the new muscle will be wrapped in the titanium splint. "Titanium bone" is like real bone, and even titanium artificial bone can be used instead of bone to treat fractures.

Tuesday, September 22, 2020

The plastics industry is the second largest user of titanium dioxide

When the hydrogen content in the titanium tube is too high, the brittleness of the titanium tube will reduce the impact of toughness and notched tensile strength of the titanium tube. Therefore, the hydrogen content in titanium pipe joints should not be higher than 0.015%. In order to reduce hydrogen absorption, fingerprints, abrasion marks, grease and other residues should be removed before heat treatment. There is no steam in the heat treatment furnace. When the hydrogen content of the titanium tube is higher than the allowable value, vacuum annealing cleaning is required.
When the temperature is not higher than 540°C, the oxide film will not thicken, but at a higher heat treatment temperature, the oxidation rate of the oxide film will increase, and the internal diffusion layer of the oxide film will become a pollution layer. The oxygen contamination layer has a high brittleness ratio, which causes cracks and damage on the surface of the part. Deoxidation pollution layer includes mechanical processing, pickling, chemical polishing and so on. During heat treatment, the heating time should be shortened as much as possible while protecting the heat treatment. It can also be carried out in a vacuum furnace or an inert gas furnace. The pollution caused by the heating of titanium pipe fittings in the air furnace should be avoided or appropriately reduced.
Features of titanium tube:
1 Corrosion resistance of titanium pipe joints. Titanium is a very active metal with a very low equilibrium potential and a strong tendency to thermodynamic corrosion in the medium. Titanium has good stability and corrosion resistance in oxidizing, neutral and weakly reducing media.
2 Titanium pipe joints have good heat resistance. It can be used for a long time at 600℃ or high temperature.
3Non-magnetic, non-toxic and titanium alloy pipe fittings are non-magnetic metals and will not be magnetized in a large magnetic field.

Sunday, September 20, 2020

Titanium alloy parts processing plays an important role in machinery manufacturing

Small-sized bars of titanium and titanium alloys are generally produced by rolling. However, during heating, rolling, and heat treatment, due to uneven distribution of temperature and plastic workability, as well as shearing, transportation and stacking, etc. Different degrees of bending is often produced. At this time, the titanium rod must pass through the straightening place to ensure that the bending degree of the rod can meet the requirements of use.
The commonly used straightening methods for titanium rod processing include pressure straightening and roller straightening, while small-sized bars generally use roller straightening, which has higher efficiency. However, for small-sized titanium and titanium alloy bars, the desired effect is often still not achieved after repeated straightening, and the problem of direct fracture during the straightening process often occurs.
The room temperature elastic modulus of commonly used titanium and titanium alloys is mostly lower than 120GPa. Therefore, titanium and titanium alloy bars will undergo greater elastic deformation under stress conditions under relatively small rolling production, and the rebound will be large. He plastic is easy to straighten, and the yield ratio of many titanium alloys is between 09-1. For reasons such as straightening, it is easy to break during straightening. Therefore, titanium and titanium alloy bars generally require hot straightening at the over-straightening point to ensure the straightening effect.