A rare but very important metal in many industries - zirconium - was first isolated only in 1824. However, it still contained a certain percentage of other elements. Only in the 20th century was it possible to obtain pure zirconium free of various impurities. Alloys based on it are successfully used for the manufacture of refractories, abrasives, ceramic paints, sandpaper, textiles, deodorants and artificial stones. Of course, one cannot forget about the high importance of this metal in medicine. We learn about it in more detail.
Metallurgy development
Zirconium is the main component of alloys for nuclear power. But for this it is necessary that it be as pure as possible from various impurities. The fact is that not only such a rare-earth element as hafnium is present in zirconium ores, but also nitrogen, carbon and oxygen. And such impurities of non-metals are quite dangerous and can be included in the composition of structural materials for nuclear reactors in an amount of not more than millionths of a percent. Therefore, obtaining pure zirconium and alloys based on it is a rather long and laborious process. First, the concentrate is opened, then it is enriched, unwanted impurities and hafnium are separated.
Pure zirconium looks like a typical metal. In appearance, it is very similar to steel, but at the same time more durable and ductile. Of course, in alloys based on it, its characteristics can vary significantly depending on the number of other elements. For example, oxygen (greater than 0.6%) will make zirconium more fragile. But there is also the flip side of the coin: the dioxide of this metal (ZrO 2 ) has a melting point of 2680 ° C.
The main structural material
As mentioned earlier, the widest area where zirconium and its alloys are used is the nuclear industry. Their main advantage is that they have a small thermal neutron capture cross section (only 0.18 barn), good corrosion properties and a high melting point. So, the fuel rod is the main structural fuel element of the active zone of a nuclear reactor in which nuclear fuel is placed . It is in it that fission of heavy nuclei occurs, which means that the fuel rod must be made of the most durable and refractory metal, and it should not change the nature of neutron absorption in the reactor.
So, for the manufacture of its shell using zirconium alloys. The requirements for them are quite stringent. So, alloying elements should not degrade its characteristics. This is especially true for the small capture cross section of thermal neutrons. Zirconium is alloyed in order to suppress the harmful effects of nitrogen and improve its corrosive properties. Many elements of the periodic table are not suitable, as they reduce certain characteristics.
The most famous alloy used for the manufacture of a fuel rod is a compass. Its main alloying element is tin, and auxiliary elements are iron, chromium and nickel. In Russia, niobium is most often used for doping zirconium . It also has a small thermal neutron capture cross section, reduces hydrogen absorption and forms only solid solutions. And this, in turn, provides alloys with high ductility.
Zirconium alloying
The high corrosion resistance of this metal explains why it is so often used as an alloying element in ferrous and non-ferrous metallurgy. In addition, it is insoluble in hydrochloric and nitric acids and alkalis. Thus, multicomponent alloys of zirconium with magnesium are very popular. In addition, alloying with this metal increases the resistance to titanium acids. Alloys of zirconium with copper have high strength and electrical conductivity. Quite often, it is also used as an additive in the production of various grades of steel. This allows you to remove sulfur, nitrogen and oxygen from them.
Medical industry
Considering zirconium and its alloys, one cannot fail to mention another area of their use. In the medical industry, they occupy far from the last place. More recently, steel and titanium alloys were used to manufacture implants and fixators. However, in some cases, the body rejected these metals, against the background of which an allergic reaction appeared. Modern medicine uses alloys of zirconium and titanium for the manufacture of staples, plates, implants, dentures and their fixation mechanisms.
Since this metal and its compounds do not irritate the bones and surrounding soft tissues, it is successfully used for the manufacture of jewelry. So, for example, zirconium earrings do not cause an allergic reaction and heal a wound on the earlobe no worse than gold.
Power consumption
The alloy of aluminum and zirconium has many positive characteristics and is therefore successfully used in the energy industry. The fact is that steel and copper wires weigh quite a lot, and often old supports can not withstand such a load. In 1960, in Japan, one group of scientists produced a series of aluminum and zirconium alloys. They determined that such a material can be used for a long time at high temperatures (150-230 ° C) and at the same time it will be quite light. This allows you to use it for the manufacture of high temperature wires. This increases the reliability and efficiency of electrical networks.
Other applications of zirconium-based compounds and alloys
In many antiperspirants in the composition, you can find such a component as Aluminum Zirconium Tetrachlorohydrex. It is a chemical compound that absorbs sweat and its unpleasant odor. Scientists have found that it is not absorbed into the skin, which means that it can not cause severe harm to health. Despite this, in the EU and the USA, aluminum-zirconium-tetrachlorohydrex glycine is prohibited.
Zirconium oxide is used for the manufacture of electrocorundum. It is obtained by melting in tilting electric furnaces. Zirconium electrocorundum is strong enough and allows you to process materials with high clamping force. Most often it is used for rough and rough grinding.
In general, it should be noted that zirconium and its alloys have a high melting point, resistance to chemical influences, and a small coefficient of thermal expansion. For this reason, it is actively used in a wide variety of areas.