Nickel / Cobalt superalloys are high performance materials for demanding applications that require high tensile and yield strength, and ductility, over a wide temperature range. Chrome, nickel, and cobalt are predominant elements, though many others (including aluminium, tungsten, and molybdenum) are frequently used. The alloys are poured in a vacuum to prevent oxidation during the casting process. Both nickel and cobalt can be combined to create superalloys capable of being used in even the most difficult situations. An example is Alnico, a blend of iron, aluminium, nickel and cobalt, used to create permanent magnets. These magnets can be found in electric motors and magnetron tubes, or in turbine blades for gas turbines and jet aircraft engines. These materials are incredibly useful in many specialised industries that require components created to withstand harsh environments and are resistance to high temperatures, corrosion, and wear and tear.