AbstractThe element titanium (Ti) is a transition metal, which for a long time was considered to be a rare metal. Since the 1940s, titanium and its billion compounds are widely used in aircraft, rockets, missiles, artificial satellites, spacecraft, ships, military industry, medical and petrochemical fields. Scientists predict that titanium will be one of the most important products for the metallurgical industry in the 21st century.
Human beings in the use of metal in the historical process, after the experience of copper, iron, aluminum, the fourth will be widely used in the metal element is which one? This metal has been predicted by scientists as titanium. This is because titanium has a high melting point, hardness, plasticity, low density, corrosion resistance and other advantages.
One, the discovery of titanium and nature
Titanium was discovered in 1791 by the British priest Grey Gower. 1795 Martin, Klaproth in the analysis of a kind of rutile, recognizing that this ore is a metal oxide, and will be named titanium metal, titanium is easy to form alloys with common metals, in many years after the discovery of the many attempts to separate it from its compounds, and will be the first time that it is found in a metal compound. In many years after the discovery, many attempts to separate it from its compounds, were unsuccessful until 1910 by the American chemist Hunt will be very pure TiCl4 and metal Na together into the high-pressure steel cylinder, the cylinder will be heated to red-hot, cooled, washed away NaCl to get the purity of titanium as high as 99.9%.
Titanium annual production table
1910
1947
1948
1955
1957
1962
1972
0.2 tons
2 tons
10 tons
17,000 tons
20,000 tons
100,000 tons
200,000 tons
Since the 1970s, titanium production has continued to rise steadily at a rate of 15 percent per year. In the United Kingdom, for example, demand for titanium has increased by at least 800 percent in 10 years.
Titanium looks like steel, with a silver gray light translation. Titanium strength, titanium alloy tensile strength of 180kg/mm3. titanium is characterized by small degree (4.51g/cm3), hardness, high melting point (1675 ° C), high purity titanium has a good plasticity, but when there are impurities present when it becomes brittle and hard. At room temperature titanium does not act with chlorine, dilute sulfuric acid, dilute hydrochloric acid and nitric acid, but can be eroded by hydrofluoric acid, phosphoric acid, molten alkali. Titanium is easily dissolved in HF + HCl (H2SO4), titanium is the most prominent properties of seawater corrosion resistance is very strong, some people will be a piece of titanium sunk to the bottom of the sea, five years later to take a look at the top of the adherence to the many small animals and seabed plants, but not at all rusted, according to the bright light shining!
Titanium and its main compounds of the application
Titanium has outstanding performance and large reserves (in the earth's crust accounted for about 0.42% of the total weight of the world ranked seventh in the world of metals, titanium-containing minerals up to 70 kinds of seawater content is 1ug / L, in the seabed nodules also contain a large amount of titanium) characteristics. At present, the use of titanium is developing rapidly, has been widely used in aircraft, rockets, missiles, satellites, spaceships, ships, military, light industry, chemical industry, textiles, medical and petrochemical fields.
Titanium powder is a very fine rocket fuel; titanium corrosion resistance, 15 times stronger than commonly used stainless steel, service life than stainless steel more than 10 times longer. Negative and positive film production in the movie, the need to use a variety of strong acids and alkalis and other drugs, they are very serious corrosion of the printing equipment, printing equipment in the gear can only be used for a few months at most, in 1980 Xi'an Film Studios trial of titanium, the results of the equipment running for more than a year, the gear did not corrode at all.
Titanium in surgical applications, but also very fascinating. At present, the surgical bone is used stainless steel, the use of stainless steel has a disadvantage, that is, after the healing of the bone, the stainless steel piece to take out again, which is a very painful thing. Otherwise, stainless steel will be rusted and harmful to the human body. If the titanium "artificial bone" will make orthopedic technology completely changed. In the head of the damaged place, with titanium and titanium screws, after a few months, the bone will grow again in the titanium piece of small holes and screws, the new muscle fibers are wrapped in titanium on the sheet, titanium bones like real bones and flesh and blood, play a supportive and reinforcing role, so titanium has been praised as a "biophilic metal". Now it has begun to be used in the knee joint, shoulder joint, rib joints, skull, active heart valve, bone fixed clamps and so on.
In the steel industry, a small amount of titanium is a good deoxidation, nitrogen and sulfur removal agent.
Titanium dioxide than titanium is a valuable white pigment called titanium white. Titanium white both lead white masking performance and zinc white lasting performance, it is one of the world's whitest substances, 1 gram of titanium white can be more than 450 square centimeters of the area coated with snow white. Especially valuable is titanium dioxide non-toxic. Now there are hundreds of thousands of tons of titanium dioxide used as pigment every year.
Because titanium dioxide has a high melting point, it is often used to make refractory glass, glaze, enamel, clay, and high-temperature-resistant labware.
How to develop uranium resources in seawater, is a big problem, seawater contains 400,000 tons of uranium, from 1956 onwards, people have only found one of the most promising uranium adsorbent - hydrated titanium dioxide, and from then on developed a set of titanium dioxide-based marine uranium technology, each gram of adsorbent has reached the adsorption of 1 milligrams of uranium level.
Titanium tetrachloride emits large amounts of white smoke in wet air. Because of this property, it is commonly used in the military as an artificial smoke agent. Especially in the ocean, water vapor, a release of titanium tetrachloride, the smoke is like a white Great Wall, blocking the enemy's line of sight.
Barium titanate crystals are widely used in ultrasonic instruments and underwater detectors. This is because with pressure chopping change shape, will produce current; once energized and will change shape. Put the barium titanate in the ultrasonic wave, it will be pressurized to produce current, by the size of the current it produces can be measured by the strength of the ultrasonic wave; on the contrary, with a high-frequency current through it, can produce ultrasonic waves.
In the use of gold to decorate crafts and daily necessities, because of their low hardness, easy to puncture and wear, can not be durable. When a layer of titanium nitride is plated on the surface of these substances, the appearance is almost exactly the same as gold plating, but it is more wear-resistant than gold and cemented carbide, and this plating is known as having "never-wearability".
Organic titanium polymers, which can be used as surfactants, dispersants, water-resistant agents or rust inhibitors.
Titanium alloys
Currently humans use four series of hydrogen storage metal, titanium is one of the cheaper one, but at present mankind has not found a more ideal "hydrogen storage metal", once the problem is solved, people can use hydrogen as fuel.
Titanium planes can reduce their weight by 5 tons and carry more than 100 passengers. In the new jet engines, titanium alloy has accounted for 18 to 25% of the weight of the entire engine; in the latest emergence of supersonic airplanes, the use of titanium accounted for almost 95% of the total weight of the entire airframe structure, so without titanium alloy it is very difficult to develop the current supersonic aircraft.
Submarines made of titanium are not only more durable than steel submarines, but also can dive to greater depths, titanium submarines can dive to 4500 meters below, which is the boundary of the steel submarine can not be exceeded. Made of titanium warships, ships, without paint, sailing in the sea water for several years will not rust. Because titanium is not a ferromagnetic substance, will not be detected by magnetic mines, this point is particularly important in the military, if there is no titanium refined heat-resistant steel, the current use of conventional weapons rifles and machine guns can only be the initial life of 4.5 seconds.
Titanium and zirconium's powerful absorption of air can be utilized to remove air and create a vacuum. Vacuum pumps made from titanium and zirconium alloys can pump air down to just one part per billion.
Titanium-niobium alloys are ideal superconducting materials. Tsinghua University has made clear, layered ink paintings of mountains and rivers using optical interference principles and ionized titanium nitride treatment.
Of the two most common types of stainless steel in use today, chromium-nickel-titanium type 18-8-1 (containing 18% chromium, 8% nickel and 1% titanium) is the most commonly used in industry.
Titanium carbide (TiC) is rather like iron carbide, with a metallic luster. It has a higher melting point and higher hardness than iron carbide. Therefore, it has practical application value.
Titanium utensils with the preservation of food, color, aroma and taste of the long-lasting; titanium cookware is lightweight, and will not rust, the most scientific and hygienic.
Titanium alloy made of high-pressure containers, can withstand 2500 atmospheric pressure.
Titanium and nickel alloys are known as "memory alloys". This alloy is made into a pre-determined shape, and then after molding treatment, if deformed by external forces, it can be restored to its original form with a little heating. This kind of alloy has been applied in many fields. Such as the U.S. Apollo spacecraft antenna, is this memory alloy; Shanghai First Medical College Affiliated Ninth People's Hospital has been used in this memory alloy for women's sterilization surgery; in addition can also be used for instrumentation, electronic devices and other fields.
Now, the biggest obstacle to the widespread use of titanium is that titanium is very difficult to smelt. Because the melting point of titanium is very high, the smelting of titanium should be carried out at higher temperatures, and at high temperatures the chemical properties of titanium has become very active, so the smelting should be carried out under the protection of inert gases, but also do not use oxygen-containing materials, which puts forward a very high demand for smelting equipment, technology. At present, about 70% of the smelted titanium is used in the manufacture of airplanes, missiles, spaceships, satellites and other aspects.
The application of titanium is only a good start, the future of titanium metal is unlimited, so titanium was awarded the title of "21st century metal".
Reference: