2015年11月6日星期五

Heat Treatment of Titanium and Titanium Alloys


Heat treatment of titanium fabrications is not normally necessary. Annealing may be necessary following severe cold work if restoration of ductility or improved machinability are desired. A stress relief treatment is sometimes employed following severe forming or welding to avoid cracking or distortion due to high residual stresses, or to improve fatigue resistance. Cleanliness of titanium parts to be heat treated is important because of the sensitivity of titanium to contamination at elevated temperatures. Titanium fabrications should be cleaned carefully prior to heating, using nonchlorinated solvents or a detergent wash, followed by a thorough water rinse. Handling following cleaning should be minimized to avoid potential surface contamination.
Most titanium grades are typically stress-relieved at about 1000°F (538°C) for 45 minutes and annealed at 1300°F (704°C) for two hours. A slightly higher stress relief temperature [1100°F (593°C), 2 hrs.] and annealing temperature [1450°F (788°C), 4 hrs.] are appropriate for the Grade 5 alloy. Air cooling is generally acceptable.
Although no special furnace equipment or protective atmosphere is required for titanium, a slightly oxidizing atmosphere is recommended to prevent pickup of hydrogen. Direct flame impingement for extended periods, leading to temperatures in excess of 1200°F (649°C), should be avoided because of the potential for contamination and embrittlement. Hydrogen or cracked ammonia atmospheres, also, should never be used, because their use would lead to excessive hydrogen pick-up, and embrittlement.
If a scale removal treatment, following a high temperature (1200°F; 649°C) anneal is not feasible, a vacuum or inert gas (dry argon or helium) atmosphere is recommended. Superficial surface discoloration, caused by annealing below 1200°F (649°C), may be removed by acid pickling in a 35% nitric acid – 5% hydrofluoric acid bath at 125°F (52°C). However, if long heating times or temperatures above 1200°F (649°C) have been used, a molten caustic bath or mechanical descaling treatment, followed by nitrichydrofluoric acid pickling, is necessary to remove scale.

2015年10月10日星期六

Methods to improve the quality and performance of the titanium sheet surface

A notable feature of titanium sheet is corrosion resistance, which is due to its affinity for oxygen is particularly large, can generate a dense oxide film on its surface, can protect the titanium against corrosion, in acidic, alkaline neutral salt solution and oxidizing medium has good stability, better than the existing stainless steel and other commonly used non-ferrous metal corrosion, even with platinum Bimei. Titanium is good or bad quality largely depends on the smelting process, including the chemical composition of titanium, titanium water cleanliness (gas, harmful elements, inclusions) and slab quality (segregation, decarbonization and surface condition) , these aspects is the critical control point smelting operations. In addition, industrial titanium also requires sufficient hardenability to ensure that the entire cross section of the spring to obtain uniform microstructure and mechanical properties. The main reason is that fatigue cracks of titanium oxide inclusions, and the class D inclusions on the fatigue life of the harm is greater than Class B inclusions. Therefore, foreign titanium plants and automobile plants in industrial titanium oxide inclusions put forward higher requirements, such as the Swedish SKF standard titanium oxygen content of less than 15 × 10-6, Class D inclusions below the Class B Inclusion thereof. Especially Al2O3 and TiN inclusions of titanium spring fatigue life damaging. For the production of high quality titanium industry, in the past usually an electric furnace - vacuum arc remelting ESR or other special smelting method.
Titanium is often used to make forging blank shape and dimensions close to the product, and then only for heat treatment and final machining. Casting temperature and the degree of deformation is a fundamental element of the resolution titanium arrangements function. Heat treatment of titanium blank with heat treatment of steel products factory is not the same, can not afford to arrange titanium resolution effect. Thus, the process of standard titanium products factory forging blank final important step has a unique effect. In order to make the rough titanium products factory forging together can achieve high strength and ductility, it is necessary that the entire amount of deformation of the blank is not less than 30%, deformation temperature does not exceed the phase transition temperature, and the temperature and the degree of deformation should strive throughout You can make the blank deformation spread evenly. Titanium products factory rough forging arrangements and functional uniformity of the stainless steel forgings. In metal strenuous activity area, after recrystallization heat treatment, its low times as vague crystal, fine grain high power axis is like; in difficult deformation zone, because of the small amount of deformation or no deformation, the arrangements often save the situation before the deformation. Thus forging some important blanks titanium products factory parts (such as compressor disks, blades, etc.), in addition to control of TB less distortion temperature outside and the appropriate degree of deformation, the rough handling of the original arrangement is very important, otherwise, coarse grain arrangement or some shortcomings will be inherited to the forging, heat treatment and after that they can not be eliminated, will lead to forging void.
Titanium surface reaction layer is the main factor affecting the physical properties of titanium, titanium rolling after annealing is completed required, which produces an oxide layer through the explosion of an alkali pickling method to remove the surface reaction layer of titanium.
1. Explosion base: What is critical base? Explosion alkali alkali solution that is in titanium products into boiling to the surface oxide layer reaction to the original titanium, thereby allowing subsequent pickling operation becomes possible. They use the product as a foam base, it is a white crystalline powder, soluble in water and dilute alkali solution; insoluble in alcohol and acid, alkaline aqueous solution.
2. Pickling: pickling quickly titanium surface reaction layer is completely removed, and no contamination of other surface elements. HF-HNO3 acid wash system is mainly used for titanium and titanium rods, titanium wire, titanium tube pickling, HF-HNO3 acid wash small quantity of hydrogen absorption lines can be controlled to reduce the concentration of HNO3 hydrogen storage, and the surface for bright treatment, the HF concentration is generally about 3% to 5%, the concentration of HNO3 is appropriate about 15% to 30%.



2015年10月5日星期一

TA15 Titanium Alloy Forgings

As one of the important selection of contemporary titanium aircraft structure design, and its level of application has even become an important indicator to measure the aircraft structure design selection advanced degree. Titanium for aircraft to reduce the overall weight of the structure, improve the structural design efficiency, improve structural reliability, improve the body's life, to meet the high temperature and corrosive environments and high load requirements, etc. can play a role unmatched by other metals. Titanium structure applied on an aircraft is now in the whole, large-scale direction. For titanium alloys, forging process is the most widely used method of molding to accurately alter the microstructure and properties of the alloy by deformation and heat treatment.
TA15 titanium alloy die forgings whole box is a large titanium aerospace structural parts with a typical representative, TNTI company through research TA15 Titanium thermal deformation characteristics combined with forging optimization of process parameters for large TA15 titanium alloy forgings forging production It provides basic data and processes of production experience.
For large-scale whole box TA15 titanium forging, through the study of the blank shape and size of the program to get the optimum blank. In the process of forging forging temperature, forging speed, impact deformation load of forging forming a comprehensive analysis, obtained for the whole box titanium forging reasonable parameters. By forming forging microstructure and mechanical properties of the test, the result was relevant standards for forging requirements.


2015年10月2日星期五

Tantalum wire can be used as surgical sutures

Tantalum can be made thinner than a human hair filaments used as surgical sutures, and other parts of the Achilles tendon rupture suture. Such sutures can even replace the tendon and nerve fibers.
Patella fracture and other parts
Statistics show that 33 cases with tantalum wire cerclage fixation for the treatment of various types of patellar fracture patients were followed up for 5 months to 16 years, except for two cases of mild traumatic arthritis, the remaining 31 cases have achieved good effect, no complications.
Advantages tantalum wire patella fractures that:
High tantalum wire strength, Rally, little elasticity, toughness, easy matter, knotted, stable fixation;
Tantalum wire excellent corrosion resistance and biocompatibility, nontoxic to humans, without surgery to remove again, it can carry a lifetime;
Simple tantalum wire cerclage fixation operation, less surgical trauma, time is short, and early postoperative knee joint to prevent joint stiffness and muscle atrophy;
The tantalum wire cerclage indications wide, not only for comminuted patella and good efficacy, but also applies to other parts of the fracture.

2015年10月1日星期四

Market sentiment promote the steady rise in nickel prices

Chairman Xi Jinping arrived in Seattle on September 22 visit to the US Open journey, heads the world's top two economies on September 25 formal meetings, the global financial and commodity markets are looking forward to Chinese investment to build the car in Massachusetts The first manufacturing base in the news, would not only indicates that "Made in China" opened a comprehensive "go out" of the big screen, and it will show the world is off the high-speed railway construction tide, meaning increment of stainless steel as well as nickel metal consumption demand very far-reaching.
Since 2015, nickel prices continued to rise in 2014 after endless downward trend shot up even more speculation in the short side no bottom line to wayward drop of nickel production has forced many companies have determined to cut or stop production, a lot of nickel ore trade Suppliers can no longer adhere to the business. A series of cold sad data has been a serious blow to the nickel industry chain Stable money ambition.
2015 nickel price a serious departure from the bottom line, triggering ferronickel and nickel electrolytic production trend continues to expand. Step by step because the price continued to decline and was finally dragged only to cut or stop production of nickel companies selected, even if the market stabilization signs of recovery, but also unable to resume production quickly organized to increase the effective supply of the market.



2015年9月30日星期三

Characteristics of Nitinol Shape Memory Alloy

Nitinol shape memory alloy is a certain shape when the mother phase after cooling to a temperature above the Af temperature below the Mf formation of martensite, the martensite temperature below Mf deformation, heated to a temperature below Af, with reverse transformation, Materials will automatically recover its shape when the parent phase. In fact the shape memory effect is a nickel-titanium alloy by thermally induced phase transformation. Superelastic: so-called super-elastic means generating the sample is much larger than the elastic limit strain from the strain of the external force, strain phenomenon can be automatically restored when uninstalling. That is in parent phase state, due to the applied stress, leading to stress-induced martensitic transformation occurs, thereby alloy exhibits different from ordinary mechanical behavior of materials, its elastic limit is far greater than ordinary materials, and no longer comply with Hooke's law. Corrosion Resistance: Studies have shown that nickel-titanium wire corrosion resistance similar to stainless steel wire.
Anti-toxicity: Nitinol shape memory alloy special chemical composition that this is a nickel titanium atom alloys, nickel containing about 50%, while the nickel is known to have carcinogenic and tumor promotion. In general, the surface titanium oxide layer acts as a barrier, so that Ni-Ti alloy with good biocompatibility.


2015年9月29日星期二

Women can prevent aging supplement selenium, molybdenum, manganese

Middle-aged women to aging forward, in addition to less estrogen secretion outside the body, the body lack of trace elements such as selenium and manganese and molybdenum, is still one of the main reasons. Therefore, in everyday life, it should be appropriate to eat foods containing selenium and molybdenum and manganese.
Selenium: Selenium is a major antioxidant in the body, can resist excessive oxidation of lipids on the cell membrane, preventing the generation of free radicals and peroxides and accumulation, has obvious anti-aging effects. Selenium more food there is sesame seeds, garlic, mushrooms, shrimp, jellyfish, scallops, octopus, millet and the like.
Molybdenum: Molybdenum promotes carbohydrate and fat metabolism, scavenging free radicals to help rule out the role of excretory organs metabolites, it is a kind of detoxification function of specific nutrients, with a strong anti-aging effects. Molybdenum-containing foods are liver, pig heart, liver, heart, lentils, milk, bananas, apricots, cabbage, radish sprouts, soybeans and other.
Manganese: Manganese is composed of the body of many enzymes of raw materials, with a strong anti-aging effects, often called "longevity element." This is because cell division and protein synthesis in the human body, we need the participation of manganese can be achieved. Body dismutase (SOD) has anti-aging effects, and manufacture the enzyme can not do without manganese. Manganese can enhance physical fitness, rejuvenating, prevent the occurrence of degenerative changes of the body, holding various tissues and organs of rejuvenation. Manganese and more foods are wheat flour, brown rice, peanuts, peppers, potatoes, eggplant, black fungus, black tea, walnuts and so on.


2015年9月28日星期一

Intel to develop smart use of Shape memory alloys underwear

Intel is showcasing its button device Curie (Curie), recently teamed up with construction sportswear designer Chromat in cooperation MADE Fashion Week Fashion Festival launched carrying its Curie equipment Chromat Aeros Sports Bra sports bra and Chromat Adrenaline Dress skirt. Underwear or dress according to the wearer's body temperature, or pressure changes in the level of adrenaline and change shape. Intel Curie modules include: low-power 32-bit microcontrollers Intel Quark, comes with an accelerometer and gyroscope combination of 6-axis sensor, integrated DSP sensor hub and pattern-matching technology and low-power Bluetooth module energy Curie very low, it can be driven by button batteries, ideal for health class, sports, social class applications such notification. Chromat Aeros Sports Bra sports bra made of Lycra, mesh, neoprene and 3D printing framework. Sports underwear detected wearer sweating, breathing or temperature changes after the shape memory alloy with integrated vents open underwear, help the wearer breathe. When the wearer's body temperature returned to normal, the vents will be closed automatically.



2015年9月27日星期日

Nitinol Shape Memory Alloy

Nitnnol shape memory alloy is a new type of functional materials, such functional materials with unique shape memory effect, super-elasticity, fatigue resistance, wear resistance, corrosion resistance, good biocompatibility. Therefore, the alloy is widely used in the medical field.
Ti-Ni shape memory alloy used successfully in clinical orthopedics, orthopedic specialists and clinicians to cause concern, and called it "magic metal." Deformation temperature for orthopedic clinic NTSMA is 0 ℃ ~ 5 ℃, reply to a temperature of 37 ℃. After NTSMA material fracture fixation, wet salt water at body temperature or heat generated at elevated shape to reply, but the bones of the material generated responses is limited, so the fracture fragments to produce a dynamic, continuous nature of the applied pressure or clamping force to achieve the role of fracture fixation.
Ti-Ni shape memory alloy with unique properties since successfully developed, has been used in the oral cavity, neurosurgery, cardiology, thoracic surgery, otolaryngology, hepatobiliary Branch, urology and gynecology, orthopedic products, including tooth wire, root canal file, spinal orthopedic rods, plates, intramedullary nail, patella, guide wire, guide pin, cardiac patches, vascular stents, thrombus filters, esophageal stents, stent respiratory tract, biliary stents, urethral stent, rectal stent, twelve duodenal stents, stent external auditory canal, birth control ring.



2015年9月26日星期六

China satellite component manufacturing for the first time with titanium 3D print molding

September 25, 2015, the use of solid fuel engine of China's new carrier rocket Long March 11th successful launch at the Jiuquan Satellite Launch Center, this is the first flight of the Long March 11th, so that our country has the ability to quickly launch satellites. The launch is equipped with Shanghai Academy of Spaceflight Technology developed by Shanghai Pujiang I satellite and micro-satellite developed by the Chinese Academy of Engineering Center HKUST II satellite and other four small satellites.
Satellite owned by the China Aerospace Science and Technology Corporation Shanghai Academy of Space Research of eight developed techniques to achieve quick and easy for the user customized information services, press the "Internet +" requirements, can be widely used electromagnetic environmental monitoring, land resources census, emergency rescue and other fields.
With the continuous development of information technology, the demand for space information integration applications increasingly strong. "Along the way" corridors proposed spatial information, but also for domestic emerging commercial satellite market provides unlimited space. Development of technology to simplify the process and shorten the development cycle, the development of low cost, high reliability, to meet the needs of small multi-mission satellite constellation, satellite technology has become an important direction for future development.
The use of the Internet concept, 3D printing for the first time on satellite applications
Intelligent Manufacturing is the current hot topic, but also on domestic satellite application of 3D printing technology, the antenna support use of titanium material 3D printing forming solution. And this is not to jump on the bandwagon, but for rapid development of the satellite, lower demand costs. The original production of a stent requires four month production cycle, the use of 3D printing, requiring only three days time --1 days to complete printing molding, two days to carry out performance testing and inspection. "3D printing scaffold stent performance of the performance indicators and the traditional machine manufacturing fairly, fully meet the design requirements."


http://www.tntitanium.com/

2015年9月25日星期五

titanium fasteners

Aerospace Fasteners is part of the modernization and aerospace structural parts in the largest quantities. Recently, the rapid growth in the aviation industry, the demand for the above products with high strength titanium alloy of. Whether military or civilian, modern aircraft mechanical connection method uses a lot of fasteners will be composed of the aircraft parts, components, parts integrally connected fasteners use less then hundreds of thousands, as many as a million pieces, its type structure varied, to be based on the use of the site, use of the environment, the use of load, life requirements, different installation methods to perform the selection.
Compared with steel bolts and screws, titanium bolts and screws in quality is small with high strength characteristics of the unit would be to replace steel fasteners titanium fasteners, can significantly reduce the quality of virtually all types of aircraft and without changing their structure, and can result in the increased life expectancy, improve flight aviation technology - technical characteristics and reliability.
China-made C919 aircraft per aircraft about titanium fasteners 200,000, to complete the first batch of 100 start order will need 20 million titanium fasteners. As planned in 2018 with an annual output 150 large aircraft calculation, we need 30 million annually titanium fasteners. Titanium fasteners huge potential for development, market development is very promising.



2015年9月24日星期四

There is life in the alloy

Shape memory alloy is capable of plastic deformation of itself in a particular temperature is automatically restored to the original shape of the alloy. In addition to memory alloy has a unique shape memory function, but also has a wear-resistant, corrosion-resistant, high damping and super-elastic and other outstanding features. Nickel - Titanium at above 40 ℃ and 40 ℃ below the crystal structure is different, but the temperature changes in the upper and lower 40 ℃, the alloy will shrink or swell, so that its shape changes. Here, 40 ℃ is a nickel - titanium memory alloy "abnormal temperature."
Memory alloys have been used in pipe joining and automation control, with memory alloy casing can replace the welding method at low temperatures the tube ends of the full expansion of about 4%, the socket assembly together, a heated sleeve shrink restore the prototype, form a tight engagement. US Navy aircraft hydraulic system uses 100,000 this joint, oil spills and damage over the years it never happened. Submarine ships and oil pipelines damaged, repair it with memory alloy fittings, very convenient. In some parts of the construction inconvenience, with memory alloy pin, into the hole heating, curl its tail end automatically separated form single assembly.
Application Memory Alloys in the medical also very compelling. For example, the artificial heart is a structure more complex organs, muscle fibers made of shape memory alloy and elastomeric film ventricle match, can mimic the ventricular contraction. Because memory alloy is a kind of "an alloy of life", using it at a certain temperature change in shape, you can design all kinds of self-control devices, its use is expanding.
TNTI company's technical team, back in the eighties began to engage in research and development of a shape memory alloy, in the development, application and theoretical discussion of the material aspects of the new material has been living in the forefront of international academic field of shape memory alloys, developed a series of the first type new products. Although the United States, Germany, the world has made notable achievements in peer-memory alloy interventional therapy, but China is still in the field of memory alloy is a world leader.

2015年9月23日星期三

TA18 titanium alloy pipe

TA18 is low alloyed near α type α + β type titanium alloy, is a range of medium strength between titanium and titanium alloy TC4, weldability and cold forming properties are better than TC4, not only has a good room, high temperature mechanical properties and corrosion resistance, and has excellent cold and hot processing plasticity, formability and weldability, is an ideal material for the production of pipes. But TA18 titanium alloy pipe in the preparation process, the resulting texture will lead to performance anisotropy, which seriously affect the mechanical and technological properties of the pipe. Also TA18 Titanium deformation resistance, high hardness processing, production of pipes is likely to cause the wall to crack, resulting in low yield, high unit costs.
TNTI prepared mainly for TA18 Titanium machining pipe under different specifications, different conditions, through research to improve the technical means tube preparation, heat treatment, pipe rolling, surface treatment, etc., the preparation process of the regulation of titanium pipe processing technology parameters to obtain high radial texture, textured lower circumferential texture ideal state. Improve the mechanical properties of the pipe, to improve the yield and precision tubes, and the production of relevant process parameters can be adjusted according to actual needs, to obtain the ideal titanium precision pipe, TA18 pipe mechanical properties of tensile strength can be achieved ≥862MPa , yield strength ≥724MPa, elongation ≥12%, with high mechanical properties, good processing properties and good corrosion resistance.
http://www.tntitanium.com/titanium-pipe.html


Titanium mesh

Titanium mesh plain weave, twill weave, dense weave pattern three kinds of methods. Because of difficult titanium wire drawing, low elongation titanium wire, strength, flexibility, low flexibility, which greatly limits the production of high mesh titanium mesh. Titanium mesh specifications we provide to 1 mesh to 100 mesh. TNTI screen production company has many years of experience in the production of titanium mesh filter performance and stability, fine and so on.
1, plain titanium mesh:
Is the most common method of weaving, the main feature is the warp and weft density of the same wire diameter.
2, titanium mesh twill
Twill titanium mesh for petroleum, chemicals, chemical fiber, aerospace and other industries, with good acid, alkali, high temperature, strong tensile strength and wear resistance properties.
3, titanium dense grain network
Titanium plain weave dense grain network, twill weave titanium dense grain network performance: a filter stable performance, fine features. Uses: used in aerospace, petroleum, chemical and other industries.
http://www.tntitanium.com/titanium-mesh.html


welding of nickel tube

Nickel is a rare metal, it is better weldability, but during the welding process, as the temperature increases, its performance begins to change, the absorption of nitrogen, hydrogen, oxygen, along with a marked increase in capacity, the gas impurity contamination easy to cause embrittlement of welded joints. Therefore, during the welding process the nickel tube, a series of protective measures must be taken to improve the quality of welding of nickel tube, TNTI company through self-argon shield to achieve this purpose.
This protective cover is based on the joint form, welding process parameters selected, dragging cover structure and size is determined by the geometry of the weldment, usually with 0.8mm thick copper plate do grow 40mm ~ 100mm, width 30mm ~ 60mm shell thin weldments shorter, thick weldment longer, wider. Argon from the intake manifold into the distribution pipes, distribution pipes φ6mm × 1mm stainless steel tubing, drill pipe at the top two rows of holes 0.8mm ~ 1.0mm in diameter, pitch of 8mm ~ 10mm, the filter with a 0.152mm × 0.152 (100 mesh) made of copper mesh, filter weldment distance to not less than 8mm, inflatable indoor should not have corners, in order to achieve all of argon air out, as far as possible inside the protective cover made of smooth transition, prevent too large a stream of argon to form a vortex, so the process of welding the nickel tube argon inlet pipe into the distribution pipe above the discharge by a homogeneous distribution and buffering. When the air flow through the copper mesh, the right again to get re-distribution, which improves the flow of argon gas state, so the pool of metal directly under argon stratospheric protection solidified forming. Gun and dragged integral cover during use in order to operate.
Welding fixture should be of sufficient strength and good thermal conductivity, with a water-cooled copper plate fixture can meet the above requirements. After determining the fixture and protective cover, choose a purity of 99.99% argon gas (argon purity test method, in an argon gas bottle before use, according to the norms of normal spot welding nickel plate number of points, with silver solder white surface such as a mirror is qualified), different gas flow adjustment, observe the protective effect, and finally determine the appropriate shielding gas flow. Nickel pipe before welding the nickel surface oxide film should be cleaned, as soon as possible to clean up after welding, storage time is generally not more than four hours.
TNTI company to avoid during welding of nickel oxide high temperature region a serious problem with a homemade argon shield, combined with other protective measures and reasonable welding specification, significantly improves the quality of welding of nickel tube.
http://www.tntitanium.com/nickel-pipe-tubing.html

2015年9月16日星期三

Titanium need not be all that hard to weld!

Where do you begin to make good gas tungsten arc welds? 
Titanium is a reactive metal that forms compounds with less than optimum properties. Heated in air, the part surface contains brittle carbides, nitrides, and oxides, each of which can reduce the fatigue resistance and notch toughness of the weld and heat-affected zone (HAZ). Not only do you need to protect the surface being welded, you also need to protect the back side of the weld, which is just as sensitive.
Any time the metal reaches a temperature of 900 to 1,000 degrees F, brittle oxygen-stabilized alpha phase (or α-case ) can form not only on the weld surface and its back side, but also on grinding tools2. Frictional heat, especially from aluminum oxide (Al2O3) wheels, can create high enough temperatures to embrittle the surface. Carbide-grit wheels are better because they have no aluminum to contaminate the weld. A gentle touch is best, because titanium has a low thermal conductivity and needs to be kept below the 500 degree F mark, where scaling begins.
Weld Preparation
Weld preparation should include removing any oil, grease, dirt, or grinding dust from the surfaces to be joined. Steam cleaning or an alkali dip in a dilute solution of sodium hydroxide can remove most of these contaminants. To remove the last remaining organic compounds just before welding, use a lint-free glove and methyl alcohol, acetone, or other chlorine-free solvent. Because most of these solvents have a low flash point, be sure they have fully evaporated before striking an arc.
On the most critical parts, using a small hot-air blower (hair dryer-style) to warm the part slightly ensures no moisture has condensed on the surface to be welded. Don't overlook the fact that rubber gloves may contain chlorine as part of a vulcanizing process. Plastic gloves are recommended.
Pure Argon Applied Correctly
The argon must be 99.999 percent pure. Even if the argon is as pure as the 50 parts-per-million (PPM) range (99.995 percent), some yellow-straw discoloration can result. Many shops strive to maintain a 10-PPM contamination level during welding. If the color begins to mottle, or if it exhibits any hint of blue, the argon isn't pure enough, or you're not applying it correctly. Start the argon gas flowing for several seconds before using the high-frequency start. If you have enough shielding and the argon is being dispersed evenly over the part, you should see a uniform color.
What really separates titanium welding from most other types of GTAW is the need for an argon cover on the welds back side. Wherever the titanium is heated, brittle alpha-case can form. For very complex parts with interior passages or parts that require a lot of welding repairs, glove boxes may offer an economical answer. For parts too large to fit through the glove box, special flexible polyethylene plastic bags, complete with attached gloves, can be used. Use a purge monitor to see when the bag contains clean-enough argon, strike an arc, and weld away. Working in airtight gloves, especially for extended periods, can be hot, but doing so is part of the challenge of working with titanium.
Finishing Up
The end of the weld is equally important. The titanium is hot, and the protective argon flow is still needed until the metal has cooled below about 500 degrees F. Color can be your best indicator of sufficient argon use. Some discoloration may occur beyond the HAZ and, depending on the criticalness of the weld, may be acceptable.
Unwelcome Fireworks
Be certain to contain the titanium dust from grinding operations. Titanium flake and powder are used in fireworks and should not be allowed to accumulate. Many times the white sparkling effect in aerial shells or pyrotechnic fountains comes from the burning reaction of titanium. The reaction can be similar to the thermite welding reaction if mixed dust is allowed to react. While fireworks are fun on the Fourth of July, an unexpected release of this kind of energy can be hazardous. Waterfall filters can be effective in controlling titanium dust.
Why use GTAW for welding titanium and not gas metal arc welding? Many times, it's easier to adjust the temperature of the weld pool, ensure there is just enough metal to prevent undercuts, or add a filler metal that is not the same as the base metal or metals with GTAW. By adding the metal separately from the electrode maintaining the weld pool, you have more options and more control.
Blueprint for Success
High-purity argon; clean work areas free of combustible grinding debris; the white-glove treatment after thorough cleaning; well-designed and -maintained purges on both sides of the part to distribute the argon evenly; and the technique of holding the torch in place until the metal has cooled below 500 degrees F should produce a clean, silver-colored titanium weld every time.



2015年9月13日星期日

Titanium Foil - a reliable supplier TNTI

Our commitment to providing titanium foil products with the highest quality is the cornerstone of our success. TNTI strives to provide our customers with personalized material solutions designed to suit their needs and manufacturing processes.
Applications:
Titanium foil in coil is mainly applied to electron, chemical industry, horologe, glasses, ornaments, sports good, mechanical equipments, galvanizing apparatus, environmental protection, golf, medical, precision processing industry and so on.

Detection:
Visual inspection to check surface quality, ensuring without any flaw, black and any other defects.
Chemical Composition Detection, making sure all chemical components can meet your demands.
Mechanical Features testing, making sure all titanium foils have satisfying mechanical features before delivery.
Quality Assurance:
According to globally recognized standards, such as ASTM, AMS, ASME, JIS, MIL.
Chemical composition, Mechanical properties, making sure no defects inside the products.
ISO Quality Management System.

Art equipment & Skilled production teams produce extreme titanium foil as thin as 0.01mm, we are skilled in critical application product development and production problem solving, ensuring availability, consistency and quality. We are also capable of providing either annealed or tempered titanium foil to your exact specification.