Steel alnico

Total world production of nickel is in the region of 1.0 million tonnes pa of which (1995) 25% comes from the former Soviet Union, 18% from Canada, 12% from New Caledonia and 10% from Australia. The bulk of this is used in the production of alloys both ferrous and non-ferrous. In 1889 J. Riley of Glasgow published a report on the effect of adding nickel to steel. This was noticed by the US Navy who initiated the use of nickel steels in armour plating. Stainless steels contain up to 8% Ni and the use of Alnico steel for permanent magnets has already been mentioned (p. 1114). 

Cobalt ores are often found in association with copper(II) sulfide. Cobalt is a silver-gray metal and is used mainly for alloying with iron. Alnico steel, an alloy of iron, nickel, cobalt, and aluminum, is used to make permanent magnets such as those in loudspeakers. Cobalt steels are hard enough to be used as surgical steels, drill bits, and lathe tools. The color of cobalt glass is due to a blue pigment that forms when cobalt(II) oxide is heated with silica and alumina. 

Permanent magnets such as those used in loudspeakers are made of alnico steel, an alloy of Fe,... 

In alloy steels, iron is mixed with carbon and varying amounts of other elements, mainly metals. Added metals produce desired properties such as hardness and corrosion resistance (Cr), resistance to wear (Mn), toughness (Ni), heat resistance (W and Mo), and springiness (V). Stainless steel is a well-known, corrosion-resistant alloy steel. It contains ten to 30 percent chromium and sometimes nickel and/or silicon. Because of its outstanding magnetic properties, Alnico steel is used to make permanent magnets. Alnico magnets are used in voltmeters and ammeters to rotate the cod of wire connected to the pointer. 

Other uses include the manufacture of magnetic alloys. Of these the best known is Alnico , a steel containing, as its name implies, aluminium and nickel, as well as cobalt. It is used for permanent magnets which are up to 25 times more powerful than ordinary steel magnets. 

This element does not appear in the headlines very often but it is of practical importance. Probably its greatest single use is in alloys, including stainless steels. Pure cobalt is almost as magnetic as iron and, when alloyed with aluminum, nickel, copper, and iron, the resulting Alnico alloy has a permanent magnetization far exceeding that of iron. 

In addition to its importance in alloys (for example, alnico, vicalloy, and stellite), cobalt is of use as a catalyst in the Fisher-Tropsch process in which carbon monoxide is hydrogenated to a mixture of hydrocarbons. It appears likely here that one or more carbonyl derivatives of cobalt act as intermediates. Nickel is of importance in a number of alloys Monel metal, alnico, stainless steel, etc.). In a very finely divided state Raney nickel), it is of use to the organic chemist in hydrogenation reactions, for it will absorb large quantities of hydrogen gas with probable breakage of the molecules to atoms (p. 27). 

Cobalt occurs as a number of sulfide and arsenide ores including cobaltite (CoAsS) and skutterudite ((Co,Ni)As3 which contains planar AS4-units). Production of the metal generally relies on the fact that it often occurs in ores of other metals (e.g. Ni, Cu and Ag) and the final processes involve reduction of C03O4 with A1 or C followed by electrolytic refining. Pure Co is brittle but it is commercially important in special steels, alloyed with Al, Fe and Ni (Alnico is a group of carbon-free alloys) in permanent... 

Cobalt ores are usually roasted to the oxide and then reduced with carbon or water gas. Cobalt is usually alloyed for use. Alnico is a well-known magnetic alloy and cobalt is also used to make stainless steels and in high-strength alloys that are resistant to oxidation at high temperatures (for turbine blades and cutting tools). 

Overall, this is the most significant use of cobalt, as shown in Table I (48% total use). Metallic cobalt is an important alloying element in numerous applications, such as super alloys (cobalt, nickel, iron based), magnetic alloys (soft, AlNiCo, SmCo), wear-resistant alloys, high speed steels, prosthetic alloys, and cemented carbide. 

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