The development history and application of titanium alloys
Titanium is an important structural metal that was developed in the 1950s. Titanium alloys are widely used in various fields because of their high specific strength, good corrosion resistance, and heat resistance.
Many countries worldwide, such as the United States, Japan, Russia, and China, have recognized the importance of titanium alloy materials and successfully researched and developed their practical applications.
The United States titanium industry started earlier, and its scale and technology are now in the world’s leading position. Initially, it focused on the basic research of titanium alloy materials. As a guide to the application and development of titanium alloy materials, it has made notable achievements worldwide.
The first practical titanium alloy is the United States in 1954, the successful development of Ti-6Al-4V alloy, because of its heat resistance, strength, plasticity, toughness, formability, weldability, corrosion resistance and biocompatibility are better, and become a kingpin alloy in the titanium alloy industry, the use of this alloy has accounted for all the titanium alloys 75% to 85%.
The 1950s and 1960s saw the leading development of high-temperature titanium alloys for aviation engines and structural titanium alloys for airframes. Several corrosion-resistant titanium alloys were developed in the 1970s, and corrosion-resistant and high-strength titanium alloys have been further developed since the 1980s.
The temperature of heat-resistant titanium alloys increased from 400℃ in the 50s to 600～650℃ in the 90s.
The emergence of α2 (Ti 3 Al) and γ (TiAl)-based alloys is pushing titanium use in engine parts forward from the cold end of the engine (fan and pressurized gas engine) to the hot end of the engine (turbine).
Structural titanium alloys have high strength, plasticity, toughness, modulus, and damage tolerance.
The United States aerospace industry currently uses the most titanium. In the 1980s, after the design of various advanced military fighters and bombers, the amount of titanium alloys stabilized at more than 20%.
New Progress of Titanium Alloy Research
In recent years, countries have been developing low-cost and high-performance new titanium alloys and are making efforts to make titanium alloys enter the civil industry with great market potential. The new progress of research on titanium alloy materials at home and abroad is mainly reflected in the following aspects.
High-temperature titanium alloy
The world’s first successfully developed high-temperature titanium alloy has a service temperature of only 300 350 ℃. Subsequently, IMI550, BT3-1, and other alloys with a service temperature of 400 ℃ were successively developed, as well as IMI679, IMI685, Ti-6246, Ti-6242, and other alloys with a service temperature of 450 500 ℃.
In the United Kingdom, the new high-temperature titanium alloys IMI829 and IMI834 have been successfully applied in military and civil aircraft engines.
The United States has the Ti-1100 alloy, Russia has the BT18Y and BT36 alloys, and so on. In recent years, foreign countries have used fast solidification/powder metallurgy technology and fiber or particle-reinforced composite materials to develop titanium alloys as a high-temperature development direction so that the use of titanium alloys can be increased to 650 ℃ above the temperature.
The American McDonnell Douglas Company has successfully developed a high-purity, high-density titanium alloy using rapid solidification/powder metallurgy technology. Its strength at 760 ℃ is equivalent to that of the titanium alloy currently used at room temperature.
Titanium-aluminum compound-based titanium alloys
Compared with general titanium alloys, the most significant advantages of Ti3 Al (α2) and TiAl (γ) intermetallic compounds based on titanium-aluminum compounds are good high-temperature performance (the maximum operating temperature is 816 ℃ and 982 ℃ respectively), strong oxidation resistance, good creep resistance and light weight (the density is only 1/2 of that of the nickel-based high-temperature alloys), which make them the most competitive materials for the future aero-engine and structural parts of the aircraft. These advantages make it the most competitive material for future aero-engine and aircraft structural parts.
At present, two Ti 3 Al-based titanium alloys, Ti-21Nb-14Al and Ti-24Al-14Nb-3V-0.5Mo, are in the United States to start mass production. The former has been used as high-pressure pressurized engine locks, high-pressure turbine support rings, missile tail and combustion chamber nozzle sealing pieces, etc.; the latter, through the deformation of the heat treatment, can be obtained with good strength and plasticity.
High-strength and high-toughness β-type titanium alloy
β-type titanium alloy was first developed in the mid-1950s by Crucible Company in the U.S. B120VCA alloy. β-type titanium alloy has good hot and cold machining properties, is easy to forge, can be rolled, welded, and can undergo solid solution – aging treatment to obtain high mechanical properties, good environmental resistance, and high strength.
Development and Application of Titanium Alloys in Major Fields
Development and Application of Titanium Alloys in Military Industry
Titanium is an important structural metal developed in the 1950s, and its earliest application is to provide high-performance materials for the military aviation industry.
With the development of the military industry in various countries, the application fields of titanium have been continuously broadened. So far, titanium has been used increasingly in aerospace, nuclear energy, ships, weapons, and other fields, becoming an essential strategic metal material.
Its application level has also become an essential indicator of a country’s advanced weaponry, reflecting its military level and strength.
Titanium is used in the military industry, mainly based on titanium and titanium alloys, which have excellent properties: light weight, high specific strength, high temperature resistance, and good corrosion resistance. In addition, composite materials can be matched with the structure.
In addition to the above characteristics, titanium also has high toughness, high elasticity, non-magnetic properties, and many other advantages. All these provide optional conditions for its application in the military industry.
Airplanes
Titanium alloy is one of the main structural materials of contemporary aircraft and transmitters. In the United States, in the 1980s, after the design of a variety of advanced military fighters and bombers, the titanium dosage was more than 20%.
For example, the third-generation F-15 fighter jet uses 27% titanium alloy, while the fourth-generation F-22 uses 41%.
The F-22 is a tactical fighter designed by Lockheed, Boeing, and General Dynamics. It is the world’s representative fourth-generation fighter.
For the first time, it combines the characteristics of stealth, high maneuverability and agility, and unboosted supersonic cruise into one. After the year 2000, it will serve as the main air control aircraft of the U.S. Air Force.
The F-22’s engine also uses Alloy C,E, a newly developed flame retardant titanium alloy, for the high-pressure pressurizer receiver, the fuel-charged combustion chamber barrel, and the tail nozzle.
The naval aircraft F/A-18 uses titanium alloy mainly in its bearing frame longitudinal beam, wing root and tail structure, and other key parts. The main titanium alloys used are Ti-6Al-4V and Ti-15-3 (Ti-15Mo-3Al-3Sn-3Cr).
The fuselage and wing joints are made of β-annealed Ti-6Al-4V, while the brake torque tube is made of Ti-6Al-4V casting. In addition, hot isostatically pressed Ti-6Al-4V powder metallurgy is used for landing arrestor bracket joints and engine mounts to reduce cost and improve material utilization.
Others, such as the Joint Strike Fighter (JSF), are low-cost, multi-role tactical strike fighters that will replace the U.S. Air Force’s F-16C and A-10, the Navy’s F/A-18E/F, and the Marine Corps’ F/A-18 and AV-8B.
The V-22 is a transportable tilt-rotor aircraft developed by Bell Helicopter for the Marine Corps. It features the advantages of vertical takeoff, landing, and hovering for helicopters and enhances the advantages of high-speed flight and long-range for fixed-wing aircraft.The V-22 tilt-rotor technology is comparable to that of a jet engine or helicopter.
Titanium alloy is used for the windshield sealing frame, the main engine nacelle structure, and the main firewall. Howmet replaced the original 43 elements and 536 fasteners with a monolithic titanium casting for the transmission joints, which are the main support parts of the rotor system and the engine.
Ships
Titanium in the Earth’s crust is extremely rich in storage, with its low density and high strength, and has excellent corrosion resistance, heat resistance, and low temperature performance. Titanium has a strong resistance to acid and alkali corrosion, immersed in seawater for 5 years without rusting, steel in seawater will corrode and deteriorate.
With titanium alloy for manufacturing the ship’s hull, seawater can not corrode it, making it suitable for use in submarines, which are resistant to seawater corrosion and deep pressure.
Its dive depth is increased by 80% compared to stainless steel submarines. At the same time, titanium is non-magnetic, will not be found by mines, has a good anti-monitoring role.
General steel submarines that dive more than 300 m are easily affected by water pressure. Titanium submarine diving depth of more than 300 m not only will not be crushed, but also can effectively avoid the attack of deep-water bombs, showing the “titanium submarine” unique charm and excellent performance. At present, titanium is an irreplaceable material for deep-sea ships.
As early as 1968, Russia successfully manufactured all-titanium submarines. Since the mid-1960s, Russia has produced 6 to 7 double high-pressure shell “Alpha” class all-titanium submarines, each with titanium up to 3,000 t. The “Alpha” submarine is made of titanium, which is the most powerful material in the world.
“Alpha” attack submarines, due to the use of advanced titanium alloy for the shell material, can reach a maximum depth of up to 900 m.
In addition, such as “Shark” class nuclear submarines, multi-purpose 945-type and 988-type nuclear submarines, etc., their underwater displacement, underwater speed, and diving depth limit of up to 800 m, and their pressure-resistant shell are constructed with titanium alloy.
Titanium alloy is also widely used in torpedo launching tanks, torpedo launching high-pressure cylinders, crisis coolers, pumps, valves, tubes, propellers, etc., made of titanium alloy, resulting in good performance, and the service life is greatly extended.
Combat vehicles
With the increasing threat of anti-armor, protective armor is also getting thicker and heavier; the mass of combat vehicles in the last decade increased by 15% to 20%, seriously affecting their transport capacity and mobility. Replacing rolled homogeneous armor steel with titanium alloys is an effective way to reduce weight.
In the United States, titanium alloy has been used in M1 “Abrams” main battle tanks, M2 “Bradley” combat vehicles.
For the M1 main battle tank, the U.S. Department of the Army has studied the application of many titanium alloy components and has also considered using titanium alloy instead of rolled homogeneous steel for manufacturing tanks and other parts of the technology project.
On the M2, titanium was used primarily to improve the command hatch and top attack armor. One measure to strengthen the armor was the use of forged titanium alloy additional armor in specific areas to protect against large-caliber ammunition.
Others, such as the M113 armored personnel carrier, also featured titanium add-on armor to increase the armor’s ballistic resistance.
Titanium is extensively used in two 155 mm lightweight towed howitzers in the artillery system. The future Crusader 155 mm self-propelled howitzer will also use titanium for many of its components.
The U.S. Marine Corps is pursuing various options to reduce the mass of the Advanced Amphibious Assault Vehicle, one of which is to use lightweight armor.
Another option is to use titanium alloy style steel for components such as the load wheels, counterbalance arms, and load gearboxes. Although titanium alloy has excellent performance, it is not widely used because of its high price
And can not be widely used.
In recent years, the United States has successfully developed some new low-cost military titanium alloy materials. Their mechanical properties, bullet resistance, and other indicators equal to or exceed the corresponding value of the traditional military Ti-6Al-4V titanium alloy, but their cost is lower.
These new titanium alloy materials are of great significance in promoting and expanding the use of titanium alloy in national defense.
As mentioned above, in the future combat vehicles and artillery systems, the U.S. Army will use low-cost titanium alloys to replace rolled homogeneous steel and aluminum alloys to manufacture armor and components to enhance armor and reduce weight, and its application will be gradually expanded.
Low-cost titanium alloys have great potential for application in the U.S. Navy and Air Force. Because of seawater corrosion, the U.S. Navy needs to replace about 97 km per year of the heat exchanger with copper-nickel alloy tubes.
The tube can be manufactured using titanium alloy, extending its service life and resulting in substantial savings in repair and maintenance costs. The U.S. Air Force is also interested in low-cost titanium alloys. The cold furnace melting process can reduce the cost of aerospace-grade titanium alloys.
Application of Titanium Alloy in Biomedicine
Biomedical materials is an important branch of materials science, is used for diagnosis, treatment or replacement of human tissues, organs or to enhance their functions, with high technical content and high economic value of the new carrier materials, materials science and technology is a new field under development.
Over the past 10 years, the market growth rate of biomedical materials and products has been maintained at about 20% to 25%. It is expected that in the next 10 to 15 years, the medical device industry, including biomedical materials, will reach the size of the pharmaceutical market and become a pillar industry of the world economy in the 21st century.
Titanium is non-toxic, lightweight, high-strength, and has excellent biocompatibility, making it an ideal medical metal material. Titanium and its alloys with outstanding overall performance, become artificial joints (hip, knee, shoulder, ankle, elbow, wrist, finger joints, etc.), bone trauma supplies (intramedullary nails, plates, screws, etc.), spinal orthopedic internal fixation system, dental implants, dental brackets, orthopedic wire, artificial heart valves, interventional cardiovascular stents, such as the first choice of materials for the implantation of products in the medical field.
At present, there is no better metal material for clinical use than titanium alloy. Developed countries and the world’s leading suppliers of internal implant products have attached great importance to the research and development of titanium alloys and launched a series of new medical titanium alloy materials, including biologically active titanium alloy bionic materials.
In the surface treatment of medical titanium alloy materials, we have also done a lot of patented design and development to give medical titanium alloy materials better biological activity to meet the physiological needs of the human body and achieve the purpose of early patient recovery.
The world’s population of nearly 6.5 billion, according to incomplete statistics, almost 400 million people with disabilities, 60 million people with physical disabilities, 2 billion people with dental disease, the current biomaterial device implantation of only 35 million people, the amount of joint replacement of about 1.5 million cases per year, and the actual need for the number of people who need to replace the difference is very far.
Therefore, the market demand for biomedical materials has huge potential. As the first choice of biomedical metal materials – titanium and its alloys will also greatly increase the demand, so it is imperative to improve the research and development of medical titanium alloy materials.
Application of titanium alloy in civil field
Bicycle industry
As the production of high-grade bicycle frame materials should have high strength and hardness, titanium alloy will be an excellent choice. Its mass is only 50% of that of steel, but its strength-to-mass ratio is 28.4% higher than that of chromium-molybdenum steel.
Titanium also has excellent fatigue resistance, with a fatigue limit twice that of steel. Aluminum frames are no match for titanium in this regard after a long period of use. As a high-strength, low-density titanium alloy used in bicycle frames, it not only makes the frame lighter and stronger but also more durable.
Automobile industry
Another industry where the application of titanium products is developing rapidly is the automobile industry. Automobile engine valves, connecting rods, crankshafts, exhaust pipes, suspension springs, silencers, bodies and fasteners, etc., are used in titanium or titanium alloy.
For example, the valve, with the newly developed titanium aluminum alloy, can greatly improve the engine performance, than the nickel-based alloys used in the past, the relative density of small, creep-resistant strength, with better wear resistance.
With the further development and application of titanium products, titanium parts and components will play an increasingly large role in improving automotive performance, grade, and comfort.
The requirements for safety, comfort, and long service life are becoming increasingly stringent, especially for medium —and high-grade cars, which provides great development opportunities for the application of titanium in the automobile industry.
Sports industry
The application of titanium in sporting goods, from the earliest tennis racket, badminton racket, to the last few years, the widespread use of golf heads, clubs, and racing cars, etc., has improved people’s understanding of titanium by a big step.
Titanium golf clubs, the club head market in the first few years after a substantial adjustment, is still a major pillar of the titanium civil field. The United States is growing rapidly in the golf ball and other civil supplies with titanium.
With the gradual recovery of the titanium golf clubs and heads market, the future competition in the world titanium golf market will also shift from the original price and quality competition to service and differentiation.
The most common titanium product on the market today is the tennis racket. Currently, titanium is used in tennis racquets by burying a net made of pure titanium in the racquet’s frame.
Recently, titanium has been attracting attention for new uses, such as enhancing the effect of hitting the ball with its resilience.
Mountaineering equipment and skis are becoming lighter and smaller and easier to carry. Titanium, which is characterized by its light specific gravity, high specific strength, and low impact value at low temperatures, has been widely used as a superior material for mountaineering equipment.
Titanium has been widely used as a superior material for mountaineering equipment due to its light specific gravity, high specific strength, and non-declining impact value at low temperatures.
Titanium sporting goods include fencing protective masks, swords, ice skates, fishing rods, fishing line frames, rowing parts, ski poles, snow shovels, mountaineering ice poles, mountaineering spikes, track and field running shoes used in injection molding the Ti-Fe system of the sole of the nails, and so on.
Conclusion
Titanium and its alloys are widely used in aerospace, military, marine, medical and civil applications due to their excellent properties such as high strength, low density, corrosion resistance, high temperature resistance and biocompatibility.
Titanium alloys are constantly evolving and can be expected to become an important choice for high-performance materials in the future. The application of titanium alloys enhances performance and durability, especially in aerospace, submarines, artificial joints, and high-end consumer products.
Research and development of low-cost, high-performance titanium alloys will further expand the potential for their application, driving innovation and growth in various industries.