The Nature And Temperature Of Titanium

The properties of titanium have an extremely close relationship with temperature, its existence form and purity. The dense metallic titanium is quite stable in nature, but powdered titanium can cause spontaneous combustion in the air. The presence of impurities in titanium significantly affects the physical, chemical, mechanical, and corrosion resistance of titanium. In particular, some interstitial impurities can distort the titanium lattice and affect various properties of titanium. The chemical activity of titanium at room temperature is very small, and it can react with a few substances such as hydrofluoric acid, but the activity of titanium increases rapidly when the temperature increases, especially at high temperatures, titanium can react violently with many substances. The smelting process of titanium is generally carried out at a high temperature above 800°C, so it must be operated in a vacuum or under the protection of an inert atmosphere. The physical properties of metallic titanium Titanium (Ti) is a gray metal. The atomic number is 22 and the relative atomic mass is 47.87. The arrangement of extranuclear electrons in the sublayer is 1s2 2s2 2p6 3s2 3p6 3d2 4s2. Metal mobility is between magnesium and aluminum, and it is not stable at room temperature. Therefore, it only exists in a chemical state in nature. Common titanium compounds include ilmenite (FeTiO3) and rutile (TiO2). Titanium has a relatively high content in the earth's crust, ranking ninth, reaching 5600ppm, which is converted into a percentage of 0.56%. The density of pure titanium is 4.54×103 kg/m3, the molar volume is 10.54 cm3/mol, the hardness is poor, and the Mohs hardness is only about 4, so it has good ductility. Titanium has good thermal stability, with a melting point of 1668°C and a boiling point of 3287°C. The chemical properties of titanium metal 　The reduction ability of titanium metal is extremely strong in a high temperature environment. It can combine with oxygen, carbon, nitrogen and many other elements, and it can also deprive oxygen from some metal oxides (such as alumina). Titanium combines with oxygen at room temperature to form an extremely thin and dense oxide film. This oxide film does not react with nitric acid, dilute sulfuric acid, dilute hydrochloric acid, and the king of acids-aqua regia at room temperature. It reacts with hydrofluoric acid, concentrated hydrochloric acid, and concentrated sulfuric acid.