Titanium is first discovered by British scientists Geneigeer from ilmenite ore in 1791 , in 1795 the German chemist carat Plott also discovered the element from rutile and named "Titanium ." Due to the high chemical activity of titanium , in 1910 it was discovered 120 years after it first extract the metal titanium , magnesium reduction method in 1940 had titanium sponge , from the foundation of industrial production methods titanium .
Titanium reserves in the crust is very rich , it is second only to iron, grade 1 titanium wire aluminum , magnesium, ranking fourth , more than ten times more than the sum of the common metals copper, nickel , lead and zinc. Industry for the production of titanium ore rutile , ilmenite and titanomagnetite .
Titanium metal has many excellent properties : Titanium accounted for 4.5g/cm3, only 56% of the ordinary structural steel , structural steel and strength quite ordinary or higher , the metal structure material , titanium is the highest strength .
The melting point of titanium 1668 ℃, than iron , nickel, slightly higher than aluminum , magnesium , high melting point above 1000 ℃ . Therefore, as the light metal structural materials , titanium has a much better than aluminum, magnesium alloy heat resistance , maximum temperature up to 600 ℃.
A titanium oxide layer with highly rugged surface oxide film formed in an oxidizing atmosphere , which is an oxidizing acid, alkali , salt medium , especially in wet chlorine and seawater , has excellent corrosion resistance.
Titanium has allotrope crystal structure above 885 ℃ of close-packed hexagonal lattice of β phase , the following α -phase body-centered cubic lattice . Therefore , after adding different alloying elements , titanium can be divided into α-, β- and α + β categories. Allotrope of titanium so that when adding different alloying elements can be very different performance alloys and heat treatment has a large effect .
Expansion coefficient of titanium is 8.2 × 10-6 / ℃, the smaller the general tungsten wire structure of the metal , the thermal shock when a small stress , suitable for use in temperature changing environment .
Titanium has good toughness and fatigue resistance , weldability is also very good . Good low temperature properties of titanium , at -196 ℃, low temperature brittleness is not presented , these properties are very suitable for structural use .
Thermal conductivity of titanium small , non-magnetic , superconducting properties also have some titanium , memory performance, and hydrogen storage properties and other functions.
Since titanium has a series of excellent performance, very rich in resources , after the advent of the industrial production of titanium , immediate attention by the world in general . 1947 United States take the lead in the industrialized production of titanium sponge , then produce two tons of titanium sponge , 1957 on the development of more than 15,000 tons . Japan in 1952, the former Soviet Union have begun in 1954 with an average annual production of titanium sponge . China also began trial production of titanium sponge in 1958, and now has formed a complete industrial system of titanium . Currently, there are countries in the world titanium industry mainly the United States , CIS, Japan, Britain, China and Germany.
The first is the application of titanium in military and aviation industry from the beginning . As early as 1951 the United States will be on the plane for titanium , used in aircraft to the United States in 1961 amounted to 3,940 tons of titanium manufacturing , accounting for 77% of the total amount of titanium , if the missile and space technology combined with titanium , titanium accounting 95% of the amount of material . The former Soviet Union , the United Kingdom titanium are mainly used in military and aerospace industries. In the 1970s , the excellent performance of titanium gradually generally recognized in civilian industry , titanium used in the metallurgical, chemical, electric power and other civilian industries increased year by year , the amount has been growing steadily . Now, the U.S. non- aerospace titanium has more than 30% , 50% CIS , Japan, due to historical reasons, almost all titanium for civilian industry.
China is a country very rich in titanium resources , after decades of development , titanium spring wire has been formed from titanium, titanium sponge , titanium and titanium smelting production , titanium equipment manufacturing as a whole industrial system. China titanium for the aerospace industry is also the rise of our country in the 1980s determined to promote the principle of civilian titanium , the state has taken a timely manner to support the policy , titanium industry was on the path of stable development. However, the current scale of production in China and titanium and titanium industry there is a great gap between the world's developed countries , in the civil industry is also a small amount of titanium , the reason is the superiority of titanium material has not been widely recognized , coupled with the high price of titanium material many companies can not afford to make a direct impact on the promotion of the use of titanium materials. For China 's titanium industry has been rapid development , we must vigorously publicize and promote the use of titanium metal, titanium metal material so that the superiority and the use of titanium material can bring economic and social benefits are well known.
没有评论:
发表评论