Atomic structure of titanium

　　 Titanium is located in the IVB group of the periodic table. The atomic number is 22. The nucleus is composed of 22 protons and 20-32 neutrons. The electronic structure outside the nucleus is arranged as 1S22S22P63S23D24S2. The radius of the nucleus is 5x10-13 cm.

　　 Physical properties of titanium

　　 The density of titanium is 4.506-4.516 g/cm3 (20°C), the melting point is 1668±4°C, the latent heat of fusion is 3.7-5.0 kcal/gram atom, the boiling point is 3260±20°C, and the latent heat of vaporization is 102.5-112.5 kcal/gram atom. The critical temperature is 4350°C, and the critical pressure is 1130 atmospheres. Titanium has poor thermal and electrical conductivity, which is similar to or slightly lower than that of stainless steel. Titanium has superconductivity. The superconducting critical temperature of pure titanium is 0.38-0.4K. At 25°C, the heat capacity of titanium is 0.126 cal/g atom·degree, the enthalpy is 1149 cal/g atom, and the entropy is 7.33 cal/g atom·degree. Titanium is a paramagnetic substance with a magnetic permeability of 1.00004.

　　 Titanium has plasticity. The elongation of high-purity titanium can reach 50-60%, and the reduction of area can reach 70-80%, but it has low strength and is not suitable for structural materials. The presence of impurities in titanium has a great impact on its mechanical properties, especially interstitial impurities (oxygen, nitrogen, carbon) can greatly increase the strength of titanium and significantly reduce its plasticity. The good mechanical properties of titanium as a structural material are achieved through strict control of the appropriate impurity content and the addition of alloying elements.

Chemical nature

　　 Titanium can react with many elements and compounds at higher temperatures. Various elements can be divided into four categories according to their different reactions with titanium:

　　 One type: halogen and oxygen group elements form covalent bond and ionic bond compounds with titanium;

　　 Two types: transition elements, hydrogen, beryllium, boron, carbon and nitrogen elements form intermetallic compounds and finite solid solutions with titanium;

　　 Three categories: zirconium, hafnium, vanadium, chromium, scandium and titanium form an infinite solid solution;

　　 Four categories: inert gases, alkali metals, alkaline earth metals, rare earth elements (except scandium), actinium, thorium, etc. do not react or basically do not react with titanium

It is conceivable that titanium shaped parts also have titanium components, so many properties are the same.