An alloy is a compound of two or more elements, at least one of which is a metal. A binary alloy has two components, a ternary alloy has three and a quaternary alloy has four. The result of these combinations is a metallic substance that has significant differences from its components. Alloys are often stronger, more durable and have more desirable properties than those of their individual components, such as increased hardness or malleability. This is why alloys are more often used in industrial applications. The alloy usually takes characteristics of the elements it is made from, physical properties like reactivity, density and electrical and thermal conductivity. On the other hand, the alloy’s engineering properties such as tensile and shear strength, can be very different from the original materials.
When specific qualities of metals are needed for applications such as rockets and aircrafts, alloys can be made to match predetermined sets of characteristics. In these cases, lightweight alloys with strong heat-resistance are created. There are also alloys with particular nuclear absorption qualities for use in nuclear reactors; there are alloys used as superconductors in very low temperature applications, and there are alloys which are designed to resist the corrosive effects of boiling salt water and are used in desalination plants. Most metals can be used in the forming of alloys, and there are many different alloys, including stainless steel, pewter, brass, bronze and more. Aluminum is often mixed with copper, magnesium or zinc to form alloys used in building products, rigid and flexible packaging and transportation. Alloys of all forms are used in various industries: water extraction, treatment and distribution, construction, agriculture, construction and architecture, pharmaceuticals, consumer products, and manufacturing industries including oil, petroleum and chemicals. In most of the applications in which alloy metals are used, there are no acceptable or economic alternatives to alloys.
Types of alloys include intermetallics and superalloys. Intermetallics are alloys of two or more metals which form a new compound. These are sometimes used because they have more magnetic, superconducting and chemical properties, and they can combine ceramic and metallic properties when resistance to high temperatures and hardness is more important than the toughness and ease of processing that is more often desired. Superalloys are used mostly for their high temperature creep resistance, but they also have mechanical strength, good surface stability and both corrosion and oxidation resistance. Because of these qualities, they are used in applications such as aircraft and industrial gas turbines, military electric motors, chemical processing vessels and heat exchanger tubing.
Copyright @ 2007 GeoIndus All rights Reserved