To make an alloy, could be likened to baking a cake; first you take all the ingredients; mix them together and then apply a certain amount of heat; in a certain manner; for a certain length of time – change even minor details on any of these procedural steps and you can obtain quite different results – sometimes deliberately; other times by accident or miscalculation. When you take different metals and mix them together to form an alloy; the same basic rules apply – even if on a grander scale.
Alloying metals has been going on for a very long time – at least from the times of the Bronze Age. People then knew how to obtain copper; but found it to be too soft to be of much use. By accident or deliberate experimentation; they discovered that; if they added something else; the resultant metal became much more durable. Arsenic was one of the earliest additives; later largely replaced by tin and then zinc. All these “ingredients” were difficult to source and, often, not found together in one place; this made large scale bronze production difficult to achieve.
Iron was tried as a more readily available substitute; but, even at the time of the Iron Age, the results were lacking in strength and the ability to retain a sharp cutting edge. Probably more by design than accident; “additives” were introduced to produce iron alloys with improved usage properties; steel being the culmination of the iron alloy development.
Raw nickel in its natural form oxidizes relatively quickly and easily which means there are virtually no natural stocks of this metal on the earth’s surface; like gold, deposits of nickel are deep below ground and not available to the Iron or bronze Age metal smiths (although some nickel compounds did find their way into some early bronzes). Nickel bearing ore close to the surface is believed to be delivered to Earth during the times when our planet was being hit by extremely large meteorites.
Nickel was not isolated and classified as a chemical element until 1751; despite its somewhat accidental inclusion in alloys of other metals. It was only in relatively modern days that the use of nickel in iron (ferrous) alloys to reduce corrosion risks became widespread; but, there were still no alloys that had nickel as their main constituent. The biggest spur to the development of many actual nickel alloys came from the requirements of “jet” engines (gas turbines) for metallic components with extreme resistance to high temperatures and corrosion effects.
I am not sure how the numbering nomenclature developed (nor how many numbers now exist); but, Nickel Alloy 718 is but one of many. At the extreme high temperature end; Nickel Alloy 718 is widely used for gas turbine blades and, at the cryogenic opposite end of the temperature scale it is used for storage vessels for liquefied natural gas (LNG). To know more visit.