The Secondary Aluminum for Manufactures and Future Environmental Sustainability - Essay Example

Aluminum casting alloy Name Institution Date Aluminum casting alloy Introduction As argued by Green (2007) among the non ferrous metals for instance zinc and copper, aluminium has become the most predominant non-metal used around the globe. Among the sectors the metal is used includes transport sector, construction sector, packaging industry mechanical engineering sector and electrical engineering sectors. In addition, very many fields of application are constantly been invented hence making it more demanding. Aluminium have alloys called aluminium alloys and they are categorized into three categories depending on their method of preparation.thy includes wrought non-heat treatable alloys, wrought heat treatable alloys and lastly the casting alloy. In this regard, casting alloy consists of both non- heat- treatable and heat treatable alloy. As such, casting alloy as argued by Green (2007) is the shortest channel from law materials to required products. This paper, therefore, focuses to analyze the appropriateness of aluminium casting alloy, sources of law material, how its is produced, fabricated and recycled, how it is used and lastly the economical implications for its use. Aluminium and its alloy have many outstanding attributes that leads to its wider application. In this, case according to Campbell, (2008) casting alloy has low weight and at the same time, it is substantially strong having the capacity to withstand high stress. Again aluminium is corrosion resistant thus ensuring long durability. In addition, aluminium has excellent electricity conductivity as well as thermal properties better even is that the delivertive alloys of aluminium are manufactured with high degrees of electricity resistivity. Together with being physiologically harmless aluminium is also hygienic and non–toxic as supported by Campbell (2008).Also aluminium brings satisfaction and is economical since it is decorative and displays high reflectivity. (Campbell, 2008) In addition, as pointed by Krupiński & et al. (2010) aluminium becomes easier to handle because it is non- magnetic and it has outstanding formability and can be processed in a variety of ways including through application of heat and non application of heat. At the same time, aluminium is easier to cast and is suitable for all casting processes. Aluminium and its alloys are always easier to machine. To make it strong and wear-resistant it can be coated with an artificial oxide layer hence increasing its durability. All this range of advantages makes aluminium and alloys in this case casting alloy to go through the different manufacturing process. Affordability of aluminium is easier as it is cheap and its value is accelerated by the fact that it is the most abundant metal in the earth crusts. Included to this is the high ductility making its alloys easier to use. As noted by Campbell (2008) incase the alloys are very rigid and firm annealing which is a process that reduces strength while increasing ductility of the alloy, is done (Campbell, 2008). According to International Aluminium Institute, (2009) raw materials for aluminium casting alloys can be categorized into two basic categories depending originality and numbers of uses. As such the categories include primary aluminium and secondary aluminium. Primary aluminium is that which is in its most original form such that it has never been subjected to any form of manufacturing process. According to International Aluminium Institute, (2009) primary aluminium is abundantly found on earth crust hence called earth crust’s aluminium. There has been a rapid growth of extraction of the crust aluminium since the innovation of Hall-Heroult process in 1886 by Paul Hérault and Martin Hall. Since then many industries have been set up so as to extract the metal through the basic process of electrolysis. The extracted aluminium otherwise called bauxite is impure of and therefore is purified through Bayer process to produce pure alumina (Al2O3). Bayer process was a process invented by Karl Josef Bayer in Austria in 1888 and it helped revolutionalize the production of pure aluminium metal. The Aluminium metal is then produced through reduction of alumina through the process of reduction. Following this, metal becomes ready for manufacturing of delivertive alloys. (International Aluminium Institute, 2009). Secondary aluminium on the other hand is obtained from recycling of the aluminium metal and its alloys which is later on subjected to refinement and melting.(Green, 2007) Secondary aluminium has proven to be cheap and ease to manufacture given that remelting utilizes far much less energy compared to primary aluminium. Following this the demand for secondary aluminium accelerated. Secondary aluminium mostly is obtained from scrap metal dross and chip. According to Green (2007) skimmings and dross are products obtained after melting the scrap aluminium metals. Skimmings have high content of mixed aluminium and aluminium oxide which is usually removed from both the top surface of the molten metal and the base as well as from the walls of the liquid metal containers. At the same time, dross is derived from the same material as skimmings though containing lower metal content. (International Aluminium Institute, 2009) As noted by Krupiński & et al. (2010) aluminium casting alloy is produced in the process of casting where the different cast alloy are melted and poured into hollow shapes referred to as shaping mould which are of different design and hence equally used to produce different designs. The liquid is then left to solidify either on in the shapes or freely without the shapes. The cast are produced depending on the types of equipments used. Casting can be continuous casting where the molten metal is fed directly between rotating belts or rolls or even in a rotating wheel hence producing continuous strips or bars of metals which are suitable for coiling or immediate rolling. (Krupiński & et al. 2010). Products such as aluminium foils, electric cable and wires are effectively manufactured through this process. (Krupiński & et al., 2010) As said Campbell (2008) aluminium can also be produced through shape casting where the molten metal is poured in moulds automotive parts manufacture mostly uses shape moulding. Before the liquid metal is cast, it is first treated with an appropriate alloying element depending on the intended use of the final product for instance silicon, magnesium and so on To achieve the best casting alloy it require the casting company to take note of the designer needs and they should equally consider the tools and means to tailor the alloys they have for specific performance. (Campbell, 2008) The processes involved in casting are complex and require treatment and sub processes. For instance, during melting the metal have to be treated and cleaned off as much impurities as possible with chemicals. Additionally, the produced alloy can be annealed to increase ductility while reducing strength if that particular cast alloy was very firm and rigid. Aluminium casting alloys are widely used as seen earlier in automotives and aerospace industries particularly because of less weight attributed to them. Continuously they are replacing cast iron. For example with the escalating fuel prices and environmental concerns aluminium is considered as the most ideal for production of other apparatus of land transportation vehicles. (Campbell, 2008) Some types of aluminium casting alloys are being preferred to others because of their qualities. For instance cast Al-Si alloys are some of the most widely used alloys since they are of high flexibility which is provided by high silicon content. Again, their properties such as high contribution to castability and also their perfect response to heat treatment increase their value. Majority of this alloys belong to hypoeutectic group where silicon capacity is below the eutectic. Hypereutectic alloys on the other hand, have silicon content above the eutectic therefore mostly used in application requiring high wear resistance as well as low thermal resistance. For marine application as further noted by Campbell, (2008) Al-Mg alloys are needed as they have improved corrosion resistance. At the same time, Al-Cu based cast alloys are highly recommended for some aircraft appliances that require high strength since they are substantially strong. Al-Cu cast alloy though not easily produced since it have a tendency to hot tear. (Campbell, 2008) Aluminium casting alloys manufacturing have diverse implication all over the world both in the economy and the environment either negative or positive. For instance through increased demand of secondary aluminium has lead to the general reduction of environmental degradation thus ensuring environmental sustainability. (Green, 2007).At the same time, aluminium casting alloys have had profound implication on the economy sector through making it possible for manufacturing of different product as discussed earlier. Automotive industries, building and construction, aeronautical engineering industries are among many fields that make use of aluminium casting alloys to facilitate production of quality goods and services to the consumers. In addition the scrap metal collection, refining and remelting acts as a source of income for very many people across the world leading to further improvement of the economy. (Green, 2007) Conclusion A lot of benefits are associated with aluminium casting alloys hence leading wide range of application in the world as seen in this paper. Comparing it with other aluminium alloy manufacturing cast alloy proves to be cheap to manufacture therefore being a justification to its wide application. Also given that this metal is the most abundant no-ferrous metal on earth makes it affordable and cheap as its manufacturing is equally not expensive. As such, there should be invention of cheap scrap sorting techniques hence making them available to small scale foundries. This increases the secondary aluminium for manufactures while ensuring future environmental sustainability by saving the primary aluminium reservoirs. At the same time, there should be invention of aluminium processing method that reduces environmental degradation further ensuring environmental sustainability which in turn will lead to health human living. References: Campbell F.C., (2008).Elements of Metallurgy and Engineering Alloys, New York: ASM International International Aluminium Institute, (2009). Global Aluminium Recycling: A Cornerstone of Sustainable. Development retrieved on 4th September 2013 from Green John, (2007). Aluminum Recycling and Processing for Energy Conservation and Sustainability. New York: ASM International Krupiński M. Labisz K., Dobrzański L.A., Rdzawski Z., (2010). Image analysis used for aluminium alloy microstructure investigation. Journal of Achievements in Materials and Manufacturing Engineering Vol 42 Issues 1-2 pp 59-65. Read More

Secondary aluminium on the other hand is obtained from recycling of the aluminium metal and its alloys which is later on subjected to refinement and melting.(Green, 2007) Secondary aluminium has proven to be cheap and ease to manufacture given that remelting utilizes far much less energy compared to primary aluminium. Following this the demand for secondary aluminium accelerated. Secondary aluminium mostly is obtained from scrap metal dross and chip. According to Green (2007) skimmings and dross are products obtained after melting the scrap aluminium metals.

Skimmings have high content of mixed aluminium and aluminium oxide which is usually removed from both the top surface of the molten metal and the base as well as from the walls of the liquid metal containers. At the same time, dross is derived from the same material as skimmings though containing lower metal content. (International Aluminium Institute, 2009) As noted by Krupiński & et al. (2010) aluminium casting alloy is produced in the process of casting where the different cast alloy are melted and poured into hollow shapes referred to as shaping mould which are of different design and hence equally used to produce different designs.

The liquid is then left to solidify either on in the shapes or freely without the shapes. The cast are produced depending on the types of equipments used. Casting can be continuous casting where the molten metal is fed directly between rotating belts or rolls or even in a rotating wheel hence producing continuous strips or bars of metals which are suitable for coiling or immediate rolling. (Krupiński & et al. 2010). Products such as aluminium foils, electric cable and wires are effectively manufactured through this process.

(Krupiński & et al., 2010) As said Campbell (2008) aluminium can also be produced through shape casting where the molten metal is poured in moulds automotive parts manufacture mostly uses shape moulding. Before the liquid metal is cast, it is first treated with an appropriate alloying element depending on the intended use of the final product for instance silicon, magnesium and so on To achieve the best casting alloy it require the casting company to take note of the designer needs and they should equally consider the tools and means to tailor the alloys they have for specific performance.

(Campbell, 2008) The processes involved in casting are complex and require treatment and sub processes. For instance, during melting the metal have to be treated and cleaned off as much impurities as possible with chemicals. Additionally, the produced alloy can be annealed to increase ductility while reducing strength if that particular cast alloy was very firm and rigid. Aluminium casting alloys are widely used as seen earlier in automotives and aerospace industries particularly because of less weight attributed to them.

Continuously they are replacing cast iron. For example with the escalating fuel prices and environmental concerns aluminium is considered as the most ideal for production of other apparatus of land transportation vehicles. (Campbell, 2008) Some types of aluminium casting alloys are being preferred to others because of their qualities. For instance cast Al-Si alloys are some of the most widely used alloys since they are of high flexibility which is provided by high silicon content. Again, their properties such as high contribution to castability and also their perfect response to heat treatment increase their value.

Majority of this alloys belong to hypoeutectic group where silicon capacity is below the eutectic. Hypereutectic alloys on the other hand, have silicon content above the eutectic therefore mostly used in application requiring high wear resistance as well as low thermal resistance. For marine application as further noted by Campbell, (2008) Al-Mg alloys are needed as they have improved corrosion resistance. At the same time, Al-Cu based cast alloys are highly recommended for some aircraft appliances that require high strength since they are substantially strong.

Read More