The Past, Present and Future of Titanium and Titanium Alloys
1. The source of titanium metal
Titanium metal was first discovered by an amateur mineralogist named Gregor in England in 1791. By 1795, the German chemist Klaprus named this unknown metal substance after the Greek god Titans. Chinese-English translation for "titanium". Titanium is abundant on the earth. There are more than 140 known titanium minerals, but the industrial applications are mainly ilmenite and rutile. Among them, China's ilmenite reserves account for 28% of the world's reserves, ranking first in the world.
Titanium is a non-toxic element recognized in the world, but its mining and production costs are high and expensive. Due to a series of qualifications such as high and low temperature resistance, strong acid and alkali resistance, high strength, and low density, it has become a special material for NASA's same rocket and satellite, and has also been used in super projects such as my country's Yutu, J-20, and Shandong aircraft carrier. After entering the civilian field in the 1980s, it has become the "Honorary Metal King" in the food utensil industry due to its natural antibacterial and biophilic properties.
my country's titanium industry started in the 1950s. By the mid-1960s, my country had built sponge titanium and titanium processing plants in Zunyi and Baoji respectively, which means that China has become one of the world's titanium industrial powers. In the 21st century, my country's titanium industry has entered a new period of accelerated development, and its titanium production capacity ranks among the top in the world.
2. The difference between pure titanium and titanium alloy
Pure titanium:
Or called industrial pure titanium or commercial pure titanium, it is graded according to the content of impurity elements. It has excellent stamping process performance and welding performance, is insensitive to heat treatment and structure type, and has certain strength under satisfactory plasticity conditions. Its strength mainly depends on the content of interstitial elements oxygen and nitrogen. The properties of 99.5% industrial pure titanium are: density P=4.5g/cm3, melting point 1800°C, thermal conductivity λ=15.24W/(M.K), tensile strength σ b=539MPa, elongation: δ=25% , Reduction of area ψ=25%, elastic modulus E=1.078×105MPa, hardness HB195.
Titanium alloy:
Titanium alloy is an alloy composed of titanium and other elements. It is a relatively young metal, and it has a history of only 60 to 70 years since its discovery. Titanium alloy materials have the characteristics of light weight, high strength, low elasticity, high temperature resistance and corrosion resistance, and are mainly used in aero-engines, rockets, missiles and other components. Titanium has two kinds of allotropic crystals; titanium is an isomer with a melting point of 1720°C, and when it is lower than 882°C, it has a close-packed hexagonal crystal lattice structure, called a titanium; above 882°C, it is a body-centered The cubic lattice structure, called B titanium, utilizes the different characteristics of the above two structures of titanium, and adds appropriate alloying elements to gradually change the phase transition temperature and phase content to obtain titanium alloys (itanium alloys) with different structures.
Titanium alloy elements can be divided into three categories according to their influence on the phase transition temperature: ① The elements that stabilize the a phase and increase the phase transition temperature are a stable elements, including aluminum, magnesium, oxygen and nitrogen. Among them, aluminum is the main alloying element of titanium alloy, which has obvious effects on improving the strength of the alloy at room temperature and high temperature, reducing the specific gravity and increasing the elastic modulus. ② The elements that stabilize the B phase and lower the phase transition temperature are B stable elements. It can also be divided into isocrystal and eutectoid. The former includes molybdenum, niobium, vanadium, etc.; the latter includes chromium, manganese, copper, silicon, etc. ③ The elements that have little effect on the phase transition temperature are neutral elements, such as zirconium and tin.
TA1 (American Standard Gr1)
TA1 (Gr1) titanium is the first of four commercially pure titanium grades. It is the softest and most malleable of these grades. It has maximum formability, excellent corrosion resistance and high impact toughness. Grade TA1 is the material of choice for any application requiring ease of formability and is commonly available as titanium sheet and titanium tubing.
TA2 (American Standard Gr2) grade
Because of its diverse availability and wide availability, TA2 grade titanium is known as the "workhorse" of the commercial pure titanium industry. It has many of the same qualities as TA1 grade titanium, but is slightly stronger. Both are equally resistant to corrosion. This grade has good weldability, strength, ductility and formability. This makes TA2 grade titanium rod and plate the first choice for many applications in the construction, power generation, medical industries and many more.
TA3 (American Standard Gr3) grade
This grade uses at least commercially pure titanium grades, but that doesn't make it any less valuable. Grade TA3 is stronger than grades TA1 and TA2, with similar ductility and only slight formability - but it has higher mechanical properties than its predecessors. Grade TA3 is used in applications requiring moderate strength and primary corrosion resistance, such as aerospace, chemical processing, marine industry, etc.
TA4 (American Standard Gr4) grade
TA4 grade is considered the strongest of the four commercially pure titanium. It is also known for its excellent corrosion resistance, good formability and weldability. It is used in some airframe components, cryogenic vessels, heat exchangers and other applications that require high resolution.
TA9 (American Standard Gr7) grade
Grade TA9 is mechanically and physically equivalent to Grade TA2, except that the interstitial element palladium is added to make it an alloy. Grade 7 has excellent weldability and properties and is the most corrosion resistant of all titanium alloys. In fact, it is the most corrosion resistant of the reducing acids. Grade TA9 is used for chemical process and production equipment components. TA9 has extremely strong corrosion resistance, especially in reducing acid environments.
TA9-1 (American Standard Gr11) grade
Grade TA9-1 is very similar to Grade TA1, except that a small amount of palladium is added to enhance corrosion resistance, making it an alloy. This corrosion resistance can be used to prevent crevice corrosion and reduce acids in chloride environments. Other useful properties include optimum ductility, cold formability, useful strength, impact toughness and excellent weldability. This alloy can be used in the same titanium applications as Grade 1, especially where corrosion is desired.
Ti 6Al-4V (national standard TC4, American standard Gr5, such as
Grade 5 Titanium Sheet, Grade 5 Titanium Plate, Grade 5 Titanium Bar)
Known as the "workhorse" of titanium alloys is Ti 6Al-4V or grade 5 titanium, the most commonly used of all titanium alloys. It accounts for 50% of the total titanium consumption in the world. Its usability lies in its many benefits. Ti 6Al-4V can be heat treated to increase its strength. It can be used in welded structures at service temperatures up to 600°F. This alloy has high strength for light weight, useful formability and high corrosion resistance. The availability of Ti 6AI-4V makes it an optimal alloy for use in several industries such as aerospace, medical, marine and chemical processing industries. It can be used to create the following technical content:
• Aircraft turbines
• Engine components
• Aircraft structural components
• Aerospace fasteners
• High performance automatic parts
• Marine applications
• Sports Equipment
Ti-6AL-4V ELI Titanium Bar (national standard TC4ELI, American standard Gr23) grade
Ti 6AL-4V ELI or TC4ELI grade is a higher purity form of Ti 6Al-4V. It can be made into coils, stranded wire, wire or flat wire. It is the first choice wherever high strength, light weight, good corrosion resistance and high toughness are required. It has excellent damage tolerance to other alloys. These advantages make TC4ELI grade the ultimate dental and medical grade of titanium. Due to its biocompatibility, good fatigue strength and low modulus, it can be used in biomedical applications such as implantable components. It can also be used for detailed surgical procedures such as:
• Orthopedic pins and screws
• Orthopedic cables
• Ligature Clip
• Surgical Implantation
• Orthodontic appliances
• In joint replacement
• cryogenic container
• Bone Fixation Devices
TA10 (American Standard Gr12) grade
TA10 grade titanium has an "Excellent" grade due to its high quality weldability. It is a highly durable alloy that provides great strength at high temperatures. TA10 grade titanium has similar properties to 300 series stainless steels. The alloy can be hot or cold formed using press forming, hydroforming, stretch forming or drop weight. Its ability to form in various ways makes it useful in many applications. The high corrosion resistance of this alloy also makes it invaluable for those manufacturing equipment where crevice corrosion is a concern. Grade TA10 can be used in the following industries and applications:
• Shell and heat exchanger
• Hydrometallurgical application
• High temperature chemical manufacturing
• Ocean Freight and Airline Components
Ti 5Al-2.5Sn
Ti 5Al-2.5Sn is a non-heat-treatable alloy, which can obtain good weldability and stability. It also has high temperature stability, high strength, good corrosion resistance and good creep resistance. Creep refers to the phenomenon of plastic strain occurring at high temperature for a long time. Ti 5Al-2.5Sn is mainly used in aircraft and airframe applications and cryogenic applications.
