Titanium is a lightweight, durable silver-white metal. Titanium and titanium alloys combine lightness, strength, high corrosion resistance, low thermal coefficient expansion, the ability to work in a wide range of temperatures.
Titanium has high strength, good corrosion resistance and at the same time has a relatively small mass, which makes its use indispensable in areas where the good mechanical properties of the products are important along with their mass.
Titanium is a chemical element with serial number 22, atomic weight 47.88, light silver-white metal. Density 4.51 g / cm3, Tmelt = 1668 + (-) 5 ° С, Tkip = 3260 ° С. This material combines lightness, strength, high corrosion resistance, low coefficient of thermal expansion, the ability to work in a wide temperature range.
In terms of density and specific heat, titanium occupies an intermediate place between two main structural metals: aluminum and iron. It is also worth noting that its mechanical strength is approximately twice that of pure iron, and almost six times higher than aluminum. But this material can actively absorb oxygen, nitrogen and hydrogen, which dramatically reduce the plastic properties of the metal. With carbon, titanium forms refractory carbides with high hardness.
Titanium has low thermal conductivity, which is 13 times less than the thermal conductivity of aluminum and 4 times less than iron. The coefficient of thermal expansion at room temperature is relatively small, with increasing temperature it increases.
The elastic moduli of titanium are small and exhibit significant anisotropy. Moduli of elasticity characterize the ability of a material to deform elastically when a force is applied to it. Anisotropy is the difference in the properties of elasticity depending on the direction of action of the force. With increasing temperature to 350 ° C, the elastic moduli decrease almost linearly. A small value of the elastic moduli Ti is a significant drawback, since in some cases, to obtain sufficiently rigid structures, it is necessary to use large sections of products in comparison with those that follow from the conditions of strength.
Titanium has a rather high electrical resistivity, which, depending on the content of impurities, ranges from 42 · 10-8 to 80 · 10-6 Ohm · cm. At temperatures below 0.45 K, it becomes a superconductor.
Titanium is a paramagnetic metal. Typically, in paramagnetic substances, the magnetic susceptibility decreases when heated. Magnetic susceptibility characterizes the relationship between the magnetization of a substance and the magnetic field in this substance. This material is an exception to this rule - its susceptibility increases significantly with temperature
It has a high viscosity, during machining it is prone to sticking to the cutting tool, and therefore the application of special coatings on the tool, various lubricants is required.
Titanium alloys play a large role in aviation technology, where they strive to get the most lightweight construction combined with the necessary strength. Titanium is lightweight compared to other metals, but at the same time it can work at high temperatures. From titanium alloys are made the casing, fasteners, power kit, chassis parts, various units. Also, these materials are used in the construction of aircraft jet engines. This allows you to reduce their weight by 10-25%. Compressor discs and blades, parts of the air intake and guide apparatus, and fasteners are made from titanium alloys.
Also, titanium and its alloys are used in rocket science. Due to the short-term operation of engines and the rapid passage of dense atmospheric layers in rocket science, the problems of fatigue strength, static endurance, and partly creep are largely eliminated.
Due to its exceptionally high corrosion resistance it is indispensable in some cases in the chemical industry and shipbuilding. So it is used in the manufacture of compressors and pumps for pumping such aggressive environments as sulfuric and hydrochloric acid and their salts, pipelines, valves, autoclaves, various containers, filters, etc. Only titanium has corrosion resistance in environments such as wet chlorine, aqueous and acidic chlorine solutions, so equipment for the chlorine industry is made from this metal. Heat exchangers working in corrosive environments, for example, in nitric acid (not fuming), are made of titanium. In shipbuilding, titanium is used to make propellers, sheathing ships, submarines, torpedoes, etc. Shells do not stick to titanium and its alloys, which sharply increase the resistance of the vessel during its movement.