Steel is an alloy made out of iron and carbon. The carbon percentage can vary depending on the grade and mostly it is between 0.2% and 2.1% by weight. Though carbon is the main alloying material for iron some other elements like Tungsten, chromium, manganese can also be used for the purpose. Different types and amounts of alloying element used determine the hardness, ductility and tensile strength of steel. Alloying element is responsible for maintaining the crystal lattice structure of steel by preventing dislocation of iron atoms. Thus, it acts as the hardening agent in steel. The density of steel varies between 7,750 and 8,050 kg/m3 and, this is affected by the alloying constituents too. Heat treatment is a process which changes the mechanical properties of steels. This will affect the ductility, hardness and electrical and thermal properties of steel. There are different types of steel as carbon steel, mild steel, stainless steel, etc. Steel is mainly used for construction purposes. Buildings, stadiums, railway tracks, bridges are few places among many where steel is heavily used. Other than that, they are used in vehicles, ships, planes, machines, etc. Most of the daily used house appliances are also made by steel. Now most furniture is also replaced by steel products.
Titanium is the element with the atomic number 22 and the symbol Ti. It is a d block element and present in the 4th period of the periodic table. The electron configuration of Ti is 1s2 2s2 2p6 3s2 3p64s2 3d2. Ti mostly forms compounds with +4 oxidation state, but it can also have +3 oxidation states. Atomic mass of Ti is about 48 g mol-1.
Ti is a transition metal with a shining silvery color. It is strong but has low density and also corrosion resistant and durable. It has a higher melting point of 1668 oC. Titanium is paramagnetic and has low electrical and thermal conductivities. Availability of pure Ti is rare since it is reactive with oxygen. The formed titanium dioxide layer acts as a protective layer on Ti and prevents it from corrosion. Titanium dioxide is very useful in paper, paint and plastic manufacturing industries. Though Ti is soluble in concentrated acids, it is non reactive with dilute inorganic and organic acids.
Properties of titanium make it useful in a variety of applications. Since it is not easily corroded by sea water, Ti is used to make boat parts. Further, the strength and the light weight allow Ti to use in aircraft, rockets, missiles, etc. Ti is non toxic and bio compatible, making it suitable for biomaterial applications. Ti is a precious metal, hence used to make jewelry too.