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.

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%.

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.

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.

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.

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.

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.