This report will examine and the show benefits and drawbacks of aluminium. Aluminium is one of the basic elements that are used for engineering purposes due to its wide scale of applications. Aluminium contains a number of benefits over other materials. It also includes some drawbacks and disadvantages. There are some other materials, which may provide a group of beneficial characteristics of aluminium profiles, but aluminium actually can present a complete range of benefits at once.

Benefits

There are a number of benefits concerning with aluminium material as they are summed in the following.

Lightweight

According to Edwards (2011), aluminium is one of lightest commercial metals available. This metal has a density of about one third of the density of copper or steel. Aluminium is lighter than many of other metals. Aluminium is already about one-third of weight for iron, steel, copper, or brass. This property is important and makes it easier to handle (Edwards 2011). The high ratio of strength to weight makes aluminium to be particularly important in transportation industries. According to Nagy (1994), this is because it allows fuel savings and payloads. Petroleum tankers, aircrafts and catamaran ferries are some of the best examples of the use of aluminium metal in transport industries.  Nagy (1994) also pointed out that aluminium is an attractive material to apply in different areas such as aerospace, high-rise construction, and automotive design. In addition, the lightweight characteristic of the metal, especially in other fabrications, can significantly reduce the need for lifting equipment or special handling.

Resists Corrosion                   

Chemical studies have proved that aluminium has an outstanding resistance to corrosion. In other words, Aluminium has unique characteristic that it is resistant to corrosion (Nguyen 2005). Unlike other metals such as iron, it cannot undergo rusting, which is a chemical reaction undergone by some metals upon exposure to oxygen and moisture. According to Nguyen (2005), this metal is naturally safeguarded from rusting. This unique characteristic of Aluminium is because of the formation of a thin layer of aluminium oxide on the surface of the metal when it is exposed to air (Aluminium Extruders Council 2010). This protection is further enhanced by anodizing or other finishing techniques. In various applications, the metal can be left in the mill-finished condition. If decorative finishes or additional protections are required, then the metal can be painted or anodized.

Easy to Work

Aluminium can be easily modified to different forms like sheets, foil, rod, geometric shapes and wires. The metal also exhibits an excellent plasticity and machinability, which is appropriate for cutting, spinning, bending, and roll forming, cutting, drawing, forging, and hammering. According to Aluminium Extruders Council (2010), aluminium can be milled, bored or turned readily using correct tools. Indeed, many alloys of aluminium can be worked on easily. This is one of the significant factors leading to the low cost of finished aluminium parts. This metal is also an accepted choice of material for sections of hollow extrusions that are complex. Virtually, any method of joining, such as welding, brazing, welding or soldering, is applicable (Aluminium Extruders Council 2010). A wide range of mechanical fasteners abridges the assembly of many industrial products.  Woodward (2011) pointed out that the adhesive bonding of aluminium parts is effectively used in various applications such as car bodies, aircraft components and some construction applications. Sections of extruded aluminium are joined by basic methods that are used now such as welding, soldering, or brazing, or even by using of adhesives, clips, bolts, rivets, or other fasteners. Such Integral joining methods are especially useful for particular designs (Aluminium Extruders Council. 2010).

Physical properties

Aluminium is more sensitive to environmental factors, for instance an aluminium stamping area needs to be immaculate (Nagy 1994). Aluminium welding is important feature because aluminium does not provide visible cues such as change of colours as it occurs in the steel welding. In addition, the aluminium oxide layer tends to foster the development of micro-cracks due to inclusions upon welding (Aluminium Extruders Council 2010).

Aluminium is a good conductor of heat. According to Woodward (2011), the thermal conductivity of the metal is about three times that of steel. This property is significant in heat-exchange applications, whether cooling or heating (Aluminium Extruders Council 2010). This property of the metal is effectively utilized in the manufacture of cooking utensils, automotive parts, industrial heat exchangers and air conditioning (Woodward 2011).

Aluminium is also a good conductor of electricity. In fact, the metal is one of the two popular metals that have electrical conductivity sufficient to be used as an electrical conductor (Nagy 1994). Nevertheless, the metal is only one third of copper’s weight. This implies that it conducts about twice the amount of electricity conducted by copper of similar weight (Aluminium Extruders Council 2010). In addition, the conductivity of electrical-conductivity is approximately 62 per cent that of the International Annealed Copper Standard. This property of aluminium is significant in the manufacture of transformers, power-transmission cables, bottoms of electrical bulbs and bus bars.

Another property of aluminium is that it is non-toxic. The discovery that the metal is non-toxic was made in the early days of industry (Aluminium Extruders Council 2010). This property of aluminium allows it to be used in the manufacture of cooking utensils without posing damaging impacts on the body. The metal with its smooth surface that is easy to clean encourages a hygienic environment for the processing of food. Aluminium containers and foil wrapping are extensively and safely used in direct contact with the food (Aluminium Extruders Council 2010).

Another property of the metal is its high reflectivity. The metal is a good reflector of radiant energy via the wide range of wavelengths ranging from ultra-violet through the visible spectrum to heat waves and infrared (Woodward 2011). According to Nguyen (2005), the metal has reflectivity of light of over 80 per cent. This has resulted in its wide applications in lighting fixtures. This reflectivity property of Aluminium has also resulted in its use as an insulating material (Edwards 2011). For instance, aluminium sheets used as roofing reflect higher percentage of heat. Therefore, these roofing promotes a cool interior atmosphere in summer. In winter, aluminium roofing insulates against heat loss.

Applications

Aluminium includes three main types of applications including

Building and Construction: it is used by residential windows to high-rise curtain wall (Aluminium Extruders Council 2010).

Transportation: it includes number of component parts in the automotive, truck, rail, aerospace, and marine sectors (Aluminium Extruders Council 2010).

Engineered Products: it covers numerous products from consumer goods (air conditioners) to electrical items (power units) to machinery and equipment (irrigation pipes) to food display and refrigeration (Aluminium Extruders Council. 2010).

Figure 1: Basic steps involved in extruding an aluminium profile (Aluminium Extruders Council 2010).

Drawbacks

            The first disadvantage of the metal is that can pose some potential for injury. For instance, after opening aluminium cans, the interior parts might cause injury if not handled well. According to Aluminium Extruders Council (2010), this is because of the sharp edges of the metal. This risk is not present in other types of metals used in packing food or other products.  Edwards (2011) notes that the injuries sustained from aluminium metals might require several stitches, antibiotics, and sterile dressing in order to be treated. This is a risk to both children and adults.

The second drawback of the metal is that it causes pollution. Despite aluminium products being recyclable, about half of these products end up in landfills or incinerators. This result in the need for new aluminium products made from new materials. The smelting of this metal produces nitrogen dioxide and sulfur dioxides that can lead to both acid rain and smog. The manufacturers of aluminium products should first strip mine the bauxite ore in order to obtain the alumina (Aluminium Extruders Council 2010). Besides this being a lot of work, creating aluminium products leaves behind many tons of liquid waste material. These waste materials pollute ground water and soil.

The use of aluminium brings forth various environmental conservation issues. About a third of all aluminium-manufacturing factories use coal when producing their products. About 10 per cent of all aluminium-manufacturing plants depend on fossil fuels like natural gas and oil. Despite fossil fuels being common source of energy in manufacturing industry, they are limited. Natural gas, oil, and coal are formed from decaying organic matter under the surface of the earth over millions of years. Once these fuels are exhausted, they cannot be created.

The issue of accessibility is another disadvantage associated with the use of aluminium metals. For instance, aluminium cans might preserve foods for a long time; however, opening some of these cans can be a great challenge. Products reinforced with aluminium can be extremely difficult to gain accessibility. Attempting to force accessibility might pose the risk of injury. Other packaging materials such as plastic and cardboards open easily. As such, they prevent an individual from having a can opener and other tools.

Aluminium is considered more expensive than any other metals. It is limited to particular geometric features by economical processes. Aluminium oxide also is so abrasive and aluminium itself is hard to weld and prone to strict springing back. On the second hand, using aluminium in engine blocks is drawback due to it is more expensive for manufacturing than cast iron alloys (Nguyen 2005).

Industries defects

Melting point of aluminium is much lower (6590C) than that of steel (15000C). In usual cases, temperature is insufficiently high. Bulkheads on passenger vessels may be insulated for fire resistant equivalent to steel bulkheads. Then, machinery casings must be made of steel, as lifeboat davits should not be made of aluminium alloy components.

Conclusion

This report analyzed aluminium material including benefits and drawbacks of this material. Aluminium has wide applications and it is needed in many of industries but, on the second hand, it contains some drawbacks as provided. Aluminium is one of lightest commercial metals available. This metal has a density of about one third of the density of copper or steel. Chemical studies have proved aluminium has an outstanding resistance to corrosion. In other words, Aluminium has unique characteristic that it is resistant to corrosion. The metal also exhibits an excellent plasticity and machinability, which is appropriate for cutting, spinning, bending, roll forming, cutting, drawing, forging and hammering. The metal is a good reflector of radiant energy via the wide range of wavelengths ranging from ultra-violet through the visible spectrum to heat waves and infrared. The first disadvantage of the metal is that can pose some potential for injury. For instance, after opening aluminium cans, the interior parts pose an injury.

References

Aluminium Extruders Council 2010, Aluminium Extrusion Backgrounder, viewed 7 April 2013, <  HYPERLINK “http://www.aec.org/pdfs/BackgrounderAlExt.pdf ”   http://www.aec.org/pdfs/BackgrounderAlExt.pdf  >.

Edwards, C 2011, The Disadvantages of Aluminium Can, viewed 7 April 2013, <  HYPERLINK “http://www.livestrong.com/article/259503-the-disadvantages-of-aluminium-cans/”   http://www.livestrong.com/article/259503-the-disadvantages-of-aluminium-cans/ >.

Nagy, S 1994, An investigation of the challenges and costs associated with high volume all aluminium automotive body shop, viewed 8 April 2013, <  HYPERLINK “http://dspace.mit.edu/bitstream/handle/1721.1/35044/34282306.pdf?sequence=1”   http://dspace.mit.edu/bitstream/handle/1721.1/35044/34282306.pdf?sequence=1 >.

Nguyen, H 2005, Manufacturing Processes and Engineering Materials Used in Automotive, Grand Valley State University, Grand Valley.

Woodward, R 2011, Aluminium and Aluminium Alloys – Applications, viewed 7 April 2013, <  HYPERLINK “http://www.azom.com/article.aspx?ArticleID=320”   http://www.azom.com/article.aspx?ArticleID=320 >.