The history of the development and use of titanium

From the discovery of titanium element to obtain pure product, which lasted a hundred years. And titanium plates really get use to recognize the true face of its original, it is the 1940s after the thing.
Earth's surface ten kilometers thick formations, titaniferous of six thousandths, more than 61 times the copper content in the crust is ranked tenth (ranking elements in the crust: oxygen, silicon, aluminum, iron, calcium, sodium, potassium, magnesium, potassium, titanium), just a handful of dirt from the ground, which contains a few thousandths of titanium, the world's reserves of more than ten million tons of titanium is not rare.
Titanium easy and air react at high temperatures, but the melting point up to 1668 ℃. At room temperature, titanium afraid aqua regia and dilute nitric acid corrosion, but more than 5% sulfuric acid corrosion intolerance and 7% hydrochloric acid corrosion. (Medical titanium plate  are not afraid of the water at room temperature, it was once a piece of titanium sink to the bottom, take up five years later a look, sticky above many small animals and undersea plant, but he is not rusty, still shiny.
People began to use titanium to make submarines - titanium submarines. Because titanium is very strong and can withstand high pressure, this submarine can sail at a depth of 4500 meters in the d eep sea.