Pure titanium is a silvery white metal with many excellent properties. Titanium has a density of 4.54 g/cm3, which is 43% lighter than steel and slightly heavier than the long-established light metal magnesium. The mechanical strength is similar to steel, twice as large as aluminum and five times larger than magnesium. Titanium is resistant to high temperatures and has a melting point of 1942K, which is nearly 1000K higher than gold and nearly 500K higher than steel.
Titanium is a chemically active metal. It can react with non-metals such as O2, N2, H2, S and halogen when heated. However, at room temperature, the titanium surface is prone to form a very thin and dense oxide protective film, which can resist the action of strong acid or even aqua regia and exhibit strong corrosion resistance. Therefore, in general, metals become riddled with an acid solution and titanium is safe.
Liquid titanium dissolves almost all metals and can therefore form alloys with a variety of metals. The titanium steel obtained by adding titanium to steel is tough and elastic. Titanium and metal Al, Sb, Be, Cr, Fe, etc. form interstitial compounds or intermetallic compounds.
The titanium alloy is made of airplanes that are as heavy as other metals and have more than 100 passengers. The submarine made is resistant to seawater corrosion and to deep pressure, and its dive depth is 80% higher than that of stainless steel submarines. At the same time, titanium is non-magnetic, will not be found by mines, and has a good anti-monitoring effect.
Titanium has a "probiotic" nature. In the human body, it can resist the corrosion of secretions and is non-toxic, and it is suitable for any sterilization method. Therefore, it is widely used in the manufacture of medical devices, artificial hip joints, knee joints, shoulder joints, flank joints, skull bones, active heart valves, bone fixation clips. When new muscle fibers are wrapped around these "titanium bones", these titanium bones begin to maintain normal human activity.
Titanium is widely distributed in the human body, and the content in normal human body is not more than 15 mg per 70 kg body weight, and its effect is not clear. However, the role of titanium in stimulating phagocytic cells and enhancing immunity has been confirmed.