2021年12月2日星期四

Pipe cutting and groove processing of titanium pipes!

As the application fields of titanium tubes continue to expand, so does the amount used. Our titanium pipes have been applied in construction, in order to make the construction more scientific to provide users with high-performance titanium pipes.

The research on refractory materials for casting molds has always been linked to the crucible materials for smelting titanium tubes and titanium alloy tubes. Based on dynamics, the crucible material has to be in contact with the titanium liquid for a long time during smelting, and the titanium liquid is in contact with the titanium liquid for a long time. The contact time of the holding material is much shorter, so the usable crucible material can be used as the casting material of the Grade 9 Ti3Al2.5V Titanium Tube

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

Pipe cutting and bevel processing of titanium pipes; pipe cutting and bevel processing should be carried out by mechanical processing methods in a special workplace. Use clean water with non-polluting media for cooling during processing to prevent oxidation. Processing tools should be dedicated and kept clean to prevent iron pollution. The processed nozzle should ensure that the surface is smooth and free of defects such as cracks and heavy leather. The maximum inclination of the incision plane does not exceed 1% of the pipe diameter.

Surface cleaning: Use a steel wire brush made of austenitic stainless steel to remove scale, paint, dirt, dust, and debris that can react with titanium welded tube on all welding surfaces of the titanium pipe and within 100mm near the groove. Use a grinding wheel to trim the machined surface to remove flashes, burrs, convexities and other defects.

Align and clamp the titanium pipe and fittings. The axis should not be offset, the gap should be uniform, and the titanium pipe should be prevented from being damaged and contaminated during assembly. Avoid forced pairing. Tack welding adopts the same welding process as formal welding.

Titanium tube degreasing treatment: Use celluloid sponge dipped in sulfur-free ethanol or sulfur-free acetone to degrease all the welding surfaces and the vicinity of the groove within 50mm, and there should be no residue on the surface after treatment. Welding: It should be carried out under the conditions specified in the relevant standards.

2021年11月30日星期二

Causes of black bar defects in the rolling process of TC4 titanium rods!

TC4 (Ti-6Al-4V) is a Martens a/3-type two-phase titanium alloy with good comprehensive properties, and its service temperature can reach 450. It is widely used in important structural parts of the aviation industry, such as wing blades, aero engine discs, etc. Because the TC4 titanium rod is a two-phase titanium alloy, if the composition of the microscopic area is not uniform, it will inevitably lead to abnormal macrostructure and microstructure, resulting in a significant difference between the hardness of the abnormal area and the normal area, and the overall performance of the material is uneven. Causes fatigue crack sources, brings great hidden dangers to the safety of parts, and reduces the service life of the alloy. Aiming at the black streak defect found in the low-power inspection of a TC4 titanium alloy bar product, in order to accurately determine the defect type, a metallographic microscope was used to observe the metallographic structure and determine the abnormal area of ​​the metallographic structure. Then, a scanning electron microscope was used to analyze the chemical segregation defects of molybdenum-rich and aluminum-poor areas in the black stripe area. Through the microhardness test, it is determined that the component segregation in the black stripe region is non-brittle segregation.

The experimental results show that the composition segregation and type of TC4 titanium alloy can be effectively determined according to the above method. And it is determined that this type of defect will not affect the use and can be delivered after removal. Such defects can be reduced or eliminated by controlling the selection of raw materials for titanium alloy ingots, material mixing, electrode preparation and voltage and current during smelting. The segregation of Grade 1 Titanium Bar can be divided into hard segregation (hardness higher than normal zone, also called brittle segregation) and soft segregation (hardness lower than normal zone, also called non-brittle segregation) according to the difference between the hardness of segregation site and normal zone. If there is only non-brittle segregation in the product, and all properties meet the requirements of the product standard, the product can still be delivered for use after the segregation is eliminated. Fragile segregation is not allowed to be delivered after removal, and should be discarded in batches.

A. For the black streak defects of titanium rectangular rod found by visual inspection, the structure is observed through a metallographic microscope, the defect area is not much different from the normal area, and the defect type cannot be judged; in addition, the chemical composition of the defect area of ​​the titanium rod is analyzed by scanning electron microscope. It is found that the defect area is the segregation of chemical elements rich in heavy and poor in aluminum. Finally, combined with the microhardness test, it is determined that the segregation type of TC4 titanium rod is the non-brittle segregation of rich aluminum and poor aluminum. Through microstructure observation, micro-area composition analysis and microhardness test, the composition segregation and type of TC4 titanium alloy can be effectively determined.

B. The segregation in the TC4 titanium alloy bar is a non-brittle segregation of rich and poor aluminum, which does not affect the use and can be continuously transported after cutting; by controlling the selection of raw materials, mixing and electrode preparation parameters, as well as the voltage and current during the smelting process, it can be Reduce or eliminate such defects.

2021年11月28日星期日

How to deal with surface problems with titanium wire mesh

Titanium wire mesh is difficult to be corroded due to its special metallographic arrangement and surface passivation film, making it difficult to chemically react with the medium under normal conditions, but it is not impossible to be corroded under any conditions. Titanium wire processing is in the presence of corrosive media and inducements (such as scratches, splashes, cutting slag, etc.). Titanium mesh can also be corroded by slow chemical and electrochemical reactions with corrosive media.

And under certain conditions, the corrosion rate is appropriately fast and rust phenomenon occurs, especially pitting corrosion and crevice corrosion. Therefore, during the processing operation of the titanium wire mesh, all useful methods should be adopted to prevent the corrosion conditions and inducements. happened. In fact, many rust conditions and inducements (such as scratches, splashes, cutting slag, etc.) also have obvious adverse effects on the appearance quality of titanium wire mesh, and should and must be overcome.

How to deal with the appearance of titanium wire mesh? Commonly used titanium wire mesh surface treatment skills have the following treatment methods: Titanium wire mesh surface natural whitening treatment: during the processing of titanium mesh, black oxidation occurs through coiling, binding, welding, or artificial surface fire heating. Skin. However, this method is expensive, pollutes the environment, harmful to the human body, and highly corrosive, and is gradually being screened.

Titanium wire mesh surface mirror bright treatment method: according to the messiness of titanium mesh products and user requirements, mechanical polishing, chemical polishing, electrochemical polishing and other methods can be selected to achieve the mirror luster. Gr5 Ti-6Al-4V Titanium Wire surface color treatment: titanium mesh The color not only imparts various colors to the titanium mesh products, but also adds the variety of colors to the products, and improves the wear resistance and corrosion resistance of the products.

2021年11月23日星期二

How many methods are commonly used for cutting?

Before the titanium plate is processed into shape, the material must be cut first. Titanium plate blanking also adopts conventional sawing, milling, punching and shearing methods. Due to the high strength of Ultra-Thin Titanium Alloy Sheet, it is different from aluminum alloy blanking.

Band saw. Band saw processing efficiency is high, production preparation is convenient, but it is not suitable for processing too thin materials. It is often used for cutting titanium plates with a thickness of more than 3 mm. This method does not produce edge cracks. The disadvantage is that there are burrs, which must be polished after cutting. At present, it is mostly used for trimming, trimming and end trimming processes.

Band saw cutting can be divided into three categories: friction type, semi-friction type and ordinary band saw. When the friction band saw is working, due to the high linear speed, severe friction occurs between the saw blade and the workpiece, and the temperature in the cutting zone is very high, thus reducing the cutting resistance of the material, improving the machinability and high efficiency.

The belt used for sawing titanium should have a rigid structure and have enough power to maintain a constant speed during sawing; it should be able to feed automatically, tension the band saw and provide sufficient coolant. With ordinary high-speed steel band saws, the edge can be maintained and stable results can be obtained. Saw blades with tungsten carbide blades are used for cutting particularly thick materials, which can reduce the height of burrs and the depth affected by heat.

Milling. Use a milling cutter to mill a stack of Grade 5 Ti-6Al-4V Titanium Sheets to the desired shape, and the milling head moves along the milling template, or use a large CNC sheet metal milling machine for automatic milling. For stretched edges such as concave curves or flanging, the waist is polished before forming to prevent cracks.

Cut. Manufacturing straight-line shape wool or parts can be cut on the gantry shearing machine. If an ordinary shearing machine is used, carefully check whether the equipment can shear the titanium plate. Titanium alloy plates with a thickness of less than 35 mm can already be cut to the required size under production conditions. If necessary measures are taken to avoid slipping during cutting, thicker plates can also be cut. In order to prevent slippage, a higher clamping pressure is required. On the edge of the sheared titanium plate, especially for thicker titanium plates, the linear deviation is 0.25-0.50 mm. This deviation is usually caused by insufficient shear blade rigidity. Switching to a thicker blade can sometimes overcome this defect. If you modify the stopper device, and use digital display, fine-tuning and other technologies, the cutting accuracy can also be improved. The crack depth on the edge of the titanium plate does not exceed 0.4 mm, which can be removed by grinding wheel grinding and filing. If the shearing will cause cracks in the key parts of the part, a cutting method such as a band saw should be considered. When cutting materials with gantry shears, the minimum gap between the single sides of the scissors is 2-3% of the material thickness, the cutting angle is 75°-85°, the relief angle is 2°-3°, and the inclination angle of the blade on the oblique blade shearing bed is 2 degrees-5 degrees.

Ordinary rolling shear equipment can also be used for cutting. Circular shears can cut contour lines with a large radius of curvature (the minimum radius is about 250 mm). This method is used for titanium plates with a thickness of less than 2.5 mm. The current vibrating shears are only suitable for cutting titanium plates with a thickness of about 2 mm, and the edges of the cut wool must be filed or ground, leaving a file repair margin of more than 0.25 mm. For thin materials (thickness <0.8 mm), when the quantity is not large, you can also use lever type manual shears or hand-cut materials.

Die cut. Generally, the wool material of the required shape is punched out on the punching machine at one time. Generally, for wool with a simple shape, the maximum blanking thickness is about 3 mm. The titanium plate blanking die should have sufficient rigidity, and the upper and lower die should be kept in an accurate relative position with guide posts. When manufacturing various flat parts or various shapes of wool, the minimum size of the punching hole of the titanium plate and the minimum radius of the connecting edge of the punching parts should meet the requirements.

In addition, you can also use a punching and shearing machine to cut the material. When processing pure titanium plates, use a small die to punch out crescent-shaped incisions according to the template and connect them, so as to cut out the burrs of the parts, and then repair the key edges. The edge quality and accuracy are not as good as the die. Blanking is not efficient. The advantage of punching and shearing processing is that the production preparation cycle is short, and it is often used for small batch production.

2021年11月21日星期日

What are the magical uses of titanium wire

The performance of titanium is so excellent, the role of titanium and titanium products has become more extensive. Our most common titanium products are titanium plates, titanium rods, titanium standard parts, titanium dioxide, and even titanium wires. With the continuous research and development of titanium, the application fields of titanium are becoming more and more extensive, and there are more and more titanium and titanium alloys and various titanium products. The following titanium wire manufacturers will take you to see what are the classification and uses of titanium wire.

Titanium wire can generally be divided into surgical medical titanium wire and titanium alloy titanium wire according to whether the raw material is pure titanium or titanium alloy; it can also be divided into α titanium alloy and near α type alloy according to different composition of titanium alloy, (α+β ) Type alloy, near β type alloy and β type alloy. It can also be classified according to the different properties of titanium wires, and can also be classified according to others, but other titanium spring wire are classified according to less, and specific adjustments can be made according to the parameters of each industry.

The basic characteristics of titanium, corrosion resistance, high hardness, no magnetism, high temperature resistance, low temperature, etc., these series of functions have led to a wide range of application fields of titanium products. At present, the focus of titanium application fields is still in aviation and aerospace. , Chemical, medical, automotive, construction, sports, industry, leisure and other fields, so far, titanium is still in short supply, and the development potential is still very large.

2021年11月16日星期二

What should be paid attention to during the cutting process of titanium plate?

In view of these chemical properties of titanium metal, what problems should be paid attention to during the cutting process of Medical Titanium Plate Grade 2? The following titanium plate manufacturers will tell you.

(1) If it is a semi-automatic cutting, the guide rail should be placed on the surface of the titanium plate, and then the cutting machine should be placed on the guide rail, paying attention to the order not to be reversed.

(2) The cutting parameters should be appropriate, and should be reasonably determined according to the thickness of the titanium plate, so as to obtain a good cutting effect.

(3) Check whether the cutting nozzle is unblocked. If there is a blockage, it should be cleared in time.

(4) Before cutting the Titanium Clad Copper Sheet, the surface should be cleaned and a certain space should be left, which can facilitate the blowing of slag.

(5) The distance between the cutting nozzle and the surface of the titanium plate should be appropriate, too close or too far is not good.

(6) The preheating of the titanium plate should be sufficient, so as not to affect the cutting process.

(7) If you are cutting workpieces of different sizes, you should cut small pieces first, and then large pieces.

2021年11月14日星期日

Current Status of Domestic Titanium and Titanium Alloy Antifouling Technology

On the one hand, the domestic market for antifouling paints for large-scale ocean-going ships has been monopolized by international multinational companies. On the other hand, my country’s own antifouling coating technology has been in a position of backwardness, imitating and tracking development for a long time. Therefore, my country’s own brand of grade 5 titanium plate Products can only seek survival and development in the cracks between warship painting and the offshore fishing market. So far, the antifouling paint products of our country's independent brands are still dominated by traditional soluble antifouling paints such as blue antifouling paint and chlorinated rubber antifouling paint, and such antifouling paints have been banned and abandoned in developed countries. Compared with developed countries in Europe and the United States, there is still a significant gap in the domestic technological level.

In recent years, the literature and patent reports on new antifouling coatings at home and abroad are very impressive, involving Wuxi self-polishing, controllable dissolution type, biological antifouling, chemical bionics, nano slow-release, alkaline antifouling, biological enzyme antifouling, Low surface energy, conductive anti-fouling, structural bionics, fluorescent anti-fouling and other technical features of Nuoduo. In summary, it can be attributed to two series of release antifouling coatings and non-release antifouling coatings. The release type is still based on the design concept of self-polishing or dissolving antifouling paint, focusing on the research and development of biological extracts or artificially synthesized bionic antifouling agents, as well as biological enzymes and strong substances as antifouling agents, and then developing nano slow-release technologies. The controllable and effective release of various low-toxic, environmentally-friendly antifouling agents in the coating is well-realized, and the purpose of high-efficiency antifouling is achieved. Non-releasing series of antifouling paints such as low surface energy, conductive antifouling, structural bionics, fluorescent antifouling, etc. rely on the specific physical mechanism of the coating to achieve a non-toxic and long-lasting antifouling function map.

Low surface energy antifouling coatings have received more and more attention due to their non-toxic and unique antifouling mechanism. The Luoyang Ship Material Research Institute of my country has been more mature in the research of low surface energy antifouling coatings and has already provided a variety of products for ship antifouling use. However, such coatings have problems such as poor compatibility with primers and poor recoatability. At present, researches on modification of such coatings are being carried out at home and abroad in order to obtain better antifouling effects.

The capsaicin antifouling paint developed by the Second Institute of Oceanography, State Oceanic Administration of my country, is a composite of biologically active substances extracted from natural non-polluting peppers and organic clay. It will not kill attached marine organisms, but only To drive away. The coating has been tested on 7 ships in the South China Sea, the East China Sea, the Yellow Sea, and the North Pacific Ocean. The results show that the capsaicin antifouling paint has obvious antifouling effects.

my country's oceans are vast and there are many types of marine organisms attached, including lime worms, oysters, barnacles, various algae, and branch worms. If Titanium Alloy Rectangular Tube is used in seawater environments, corresponding anti-fouling measures must be adopted.

A variety of methods to prevent marine organism fouling have been studied, such as antifouling paint antifouling, electrolytic seawater antifouling, ultrasonic antifouling, biological antifouling, and low surface free energy antifouling methods. At present, the following measures can be adopted to solve the growth of marine organisms in China:

(1) The sub-exudation type coatings currently used in domestic ships can be used, and the antifouling period is 3 years.

(2) The use of electrolytic seawater for anti-fouling: that is, electrolysis of seawater produces chlorine gas, which is dissolved in water and becomes ClO-1, which is an unstable strong oxidant. As long as its concentration reaches 0.01PPm, it can ensure that sea creatures do not adhere, or Be killed. As hypochlorous acid is extremely unstable, it will soon become NaCl and return to the sea, so it will not pollute the environment.

(3) The use of electrolytic copper and aluminum electrode comprehensive anti-fouling technology: because cuprous oxide is an effective substance to inhibit biological adhesion, copper anodes can be installed on small and medium-sized ships, and Cu + ions are generated by electrolysis through small direct current. When the concentration reaches 5PPb, the adhesion of marine organisms can be prevented. The electrolytic aluminum anode biologically produces Al(OH)3 glue, which can maintain Cu + and make its effect longer. At the same time, Al(OH)3 is attached to the tube wall to prevent corrosion.

The production of titanium rods requires a heat treatment process

The production of titanium rods usually requires a heat treatment process to improve the material properties of the titanium alloy, remove i...