Tuesday, March 30, 2010

The Differences Between Aluminum Steel & Wrought Iron

Steel is more effective at dampening noises and vibrations than aluminum, especially with airborne noise.


Aluminum and steel are two metals commonly used in construction and various products. Wrought iron was once common, but has mostly been replaced by different forms of steel. However, there are still some metalworkers who use wrought iron. These metals have benefits and disadvantages related to their durability, strength and flexibility.


Production


Steel is an alloy that is made out of iron. Iron is made from iron ore, processed coal, limestone and heated air. Steel is made from iron in a basic oxide furnace, with materials added to change the steel's properties.


Wrought iron is iron that is cooked until it is white hot, allowing metalworkers to reshape the iron into a different form. The iron is shaped to give it curves and patterns before it is considered "wrought."


Aluminum is made by grinding aluminum ore with caustic soda at a high temperature and pressure to release a slurry. The slurry is sent through various machines and turned into alumina. Electrical currents are sent through the alumina, turning it into metallic aluminum.


Elasticity


Steel has three times the elastic modulus of aluminum, meaning that steel only needs one third of the thickness to avoid bending. Aluminum has a higher spring back than steel and iron, meaning that the metal is more likely to move back towards its original form when bent.


Malleability


Aluminum is harder to form into specific shapes than steel and wrought iron. Mild steel is more commonly used for decorative purposes --- where the steel must be easily bent -- than wrought iron. However, wrought iron is more malleable than other forms of steel, which is why wrought iron is sometimes used for fences and railings.


Strength


Aluminum has only one third the density of steel. Steel absorbs more strain than aluminum. Steel only has half the endurance of aluminum. Aluminum does not have as much hardness as steel, so aluminum receives damage more readily. Wrought iron contains a lot less carbon than steel, with approximately 0.035 percent carbon compared to the 0.06 to 2 percent carbon found in steel. Carbon tends to make objects harder, but also makes them more brittle.


Applications


Wrought iron was once the dominant metal used for structural purposes. But steel surpassed wrought iron by the end of the 19th century. When wrought iron is used, it is usually used for decorative purposes. Aluminum is one of the most commonly used metals in the world, playing a major role in packaging, the transportation industry, as an electrical conductor and in various kinds of building parts, such as gutters and roofs.







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