• Author / Uploaded
• JoseMiguelLosa

• Categories
• Condensador
• Transporte ferroviario
• Aluminio
• Tren
• Buques

Citation preview

ALUMINIO Y SUS ALEACIONES @MANUAL DEL ALUMINIO Y SUS ALEACIONES (José Vega, Ingeniero Industrial) https://ingenieriademateriales.wordpress.com/2009/04/17/manual-del-aluminio-ysus-aleaciones/

El aluminio y sus aleaciones A pesar de que el aluminio puro es un material poco usado se da la paradoja de que las aleaciones de este material son ampliamente usadas en una grandisima variedad de aplicaciones tanto a nivel industrial como a otros niveles. Por ello pasamos a ver su clasificación, estados y designaciones más comunes:

Clasificación por su proceso 

Aluminios forjados



Aluminios fundidos

Clasificación por su estado F: Estado bruto. Es el material tal como sale del proceso de fabricación. O: Recocido. Se aplica a materiales ya sea de forja como de fundición que han sufrido un recocido completo. O1: Recocido a elevada temperatura y enfriamiento lento. O2: Sometido a tratamiento termomecánico. O3: Homogeneizado. Esta designación se aplica a los alambrones y a las bandas de colada contínua, que son sometidos a un tratamiento de difisión a alta temperatura. W: Solución tratada térmicamente. Se aplica a materiales que después de recibir un tratamiento térmico quedan con una estructura inestable y sufren envejecimiento natural. H: Estado de Acritud. Viene con materiales a los que se ha realizado un endurecimiento por deformación. H1. Endurecido por deformación hasta otener el nivel deseado y sin tratamiento prosterior. H2. Endurecido en exceso por deformación y recocido parcialpar recuperar suavidad sin perder dutilidad. H3. Acritud y estabilizado. H4. Acritud y lacado o pintado. Son aleaciones endurecidas en frio y que pueden sufrir un cierto recocido en el tratamiento de curado de la capa de pintura o laca dada.

7En

ésta clasificación se usa un segundo dígito (en ocasiones es necesario un tercer dígito) que indica el grado de endurecimiento por deformación.

T: Denomina a materiales que has sido endurecidos por tratamiento térmico con o sin endurecimiento por deformación posterior. Las designaciones de W y T solo se aplican a aleaciones de aluminio ya de forja o de fundición que sea termotratables. T1: Enfriado desde un proceso de fabricación realizado a una elevada temperatura y envejecido de forma natural. T2: Enfriado desde un proceso de fabricadión realizado a una alta temperatura, tragajado en frío y envejecido de forma natural. T3: Solución tratada térmicamente, trabajada en frío y envejecida a Tamb hasta alcanzar una condición estable. T4: Solución tratada térmicamente y envejecida a Tamb hasta alcanzar una condición estable. Es un tratamiento similar a T3 pero sin el trabajo en frío. T5: Enfriado desde un proceso de fabricación a alta temperatura y envejecida artificialmente. T6: Solución tratada térmicamente y envejecida artificialmente. Son designados de esta forma los productos que después de un proceso de conformado a alta temperatura (moldeo o extrusión) no son endurecidos en frío sino que sufren un envejecimiento artificial. T7: Solución tratada térmicamente y sobreenvejecida para su completa estabilización. T8: Térmicamente tratada por disolución, trabajada en frío y envejecida artificialmente. T9: Solución tratada térmicamente, envejecida artificialmente y trabajada en frío. T10: Enfriado desde un proceso de fabricación realizado a una elevada temperatura, trabajado en frío y envejecido artificialmente hasta una condición sustancialmente estable. Existen variantes del estado T, a estas variantes se les añaden a la T dos dígitos. Estos dos dígitos son específicos para cada producto y se usan para estado de alivio de tensiones en productos fabricados mediante el proceso de forja.

Series de aluminios según sus aleantes

Las aleaciones de aluminio (tanto las forjadas como las moldeadas) se clasifican en función del elemento aleante usado (al menos el que esté en mayor proporción). Los elementos aleantes más usados son:

Serie 2xxx. En estas aleaciones el principal elemento aleante es el Cu, pero a veces tambien se le añade Mg. Las características de esta serie son: buena relación dureza-peso y mala resistencia a la corrosión. En lo referente a la primera característica decir que algunas de las aleaciones de esta serie tienen que ser sometidas a TT de solubilidad y a veces de envejecimiento para mejorar sus propiedades mecánicas. Una vez hecho esto la serie 2xxx tiene unas propiedades mecánicas que son del orden y, a veces superiores, que las de los aceros bajos en carbono. El efecto de los TT es el aumento de la dureza con una bajada de la elongación. En lo referente a la segunda característica estas aleaciones generalmente son galvanizadas con aluminio de alta pureza o con aleaciones de la serie 6xxx para protegerlas de la corrosión y que no se produzca corrosión intergranular. Los usos más frecuentes que se le dan a estos aluminios son (generalmente son usados en lugares donde sea necesario una alta relación dureza-peso) en las ruedas de los camiones y de los aviones, en la suspensión de los camiones, en el fuselage de los aviones, en estructuras que requieran buena dureza a temperaturas superiores a 150 ºc. Para finalizar decir que salvo la aleción 2219 estas aleaciones tienen una mala soldabilidad pero una maquinabilidad muy buena. Serie 3xxx.

En estas aleaciones el principal elemento aleante es el Mn. Estas aleaciones tan solo tienen un 20% más de dureza que el aluminio puro. Eso es porque el Mn solo puede añadirse de forma efectivan en solo un 1.5%. Por ello hay muy pocas aleaciones de esta serie. Sin embargo los aluminios 3003, 3×04 y 3105 son muy usados para fabricar utensilios que necesiten dureza media y que sea necesario buena trabajabilidad para fabricarlos como son botellas para bebidas, utensilios de cocina, intecambiadores de calor, mobiliario, señales de tráfico, tejados y otras aplicaciones arquitectónicas. Serie 4xxx. En esta serie el principal elemento aleante es el Si que suele añadirese en cantidades medianamente elevadas (por encima del 12%) para conseguir una bajada del rango de fusión de la aleación. El objetivo es conseguir una aleación que funda a una temperatura más baja que el resto de aleaciones de aluminio para usarlo como elemento de soldadura. Estas aleaciones en principio no son tratables termicamente pero si son usadas en soldadura para soldar otra aleaciones que son tratables termicamente parte de los elementos aleantes de las aleaciones tratables termicamente pasan a la serie 4xxx y convierten una parte de la aleación en tratable termicamente. Las aleaciones con un elevado nivel de Si tienen un rango de colores que van desde el gris oscuro al color carbon y por ello estan siendo demandadas en aplicaciones arquitectónicas. La 4032 tiene un bajo coeficiente de expansión térmica y una alta resistencia al desgaste lo que la hace bien situada para su uso en la frabricación de pistones de motores. Serie 5xxx. Esta serie usa como principal elemento aleante el Mg y a veces tambien se añaden pequeñas cantidades de Mn cuyo objetivo es el de endurecer el aluminio. El Mg es un elemento que endurece más el aluminio que el Mn (un 0.8 de Mg produce el mismo efecto que un 1.25 de Mn) y además se puede añadir más cantidad de Mg que de Mn. Las principales características de estas aleaciones son una media a alta dureza por endurecimiento por deformación, buena soldabilidad, buena resistencia a la corrosión en ambiento marino y una baja capacidad de trabajo en frío. Estas características hacen que estas aleaciones se usen para adornos decorativos, hornamentales y arquitectónicos, en el hogar, iluminación de las calles y carreteras, botes, barcos y tanques criogénicos, partes de puentes grua y estructuras de automóviles. Serie 6xxx. En estas aleaciones se usan como elementos aleantes el Mg y el Si en proporciones adecuadas para que se forme el Mg2Si. Esto hace que esta aleación sea tratable termicamente. Estas aleciones son menos resitentes que el resto de aleaciones, a cambio tiene tambien formabilidad, soldabilidad, maquinabilidad y resistencia a la corrosión. Estas aleaciones pueden modearse por un TT T4 y endurecido por una serie de acciones que completen el TT T6. Su uso suele ser el de aplicaciones arquitectónicas, cuadros de bicicletas, pasamanos de los puentes, equipo de transporte y estructuras soldadas.

Serie 7xxx. El Zn añadido en proporciones que van desde el 1 al 8 % es el elemeto aleante en mayor proporción en estas aleaciones. A veces se añaden pequeñas cantidades de Mg para hacer la aleación tratable termicamente. Tambien es normal añadir otros elementos aleantes como Cu o Cr en pequeñas cantidades. Debido a que la principal propiedad de estas aleaciones es su alta dureza se suele usar en las estructuras de los aviones, equipos móviles y otras partes altamente forzadas. Debido a que esta serie muestra una muy baja resistencia a la corrosión bajo tensión se le suele aplicar levemente un TT para conseguir una mejor mezcla de propiedades.

http://www.alumatter.info

http://aluminium.matter.org.uk/content/html/eng/default.asp?catid=2&pageid=995466854 The main properties which make aluminium a valuable material are its low density, strength, recyclability, corrosion resistance, durability, ductility, formability and conductivity. Due to this unique combination of properties, the variety of applications of aluminium continues to increase. It is essential in our daily lives. We cannot fly, go by high speed train, high performance car or fast ferry without it. Nor can we get heat and light into our homes and offices without it. We depend on it to preserve our food, our medicine and to provide electronic components for our computers. For many years the biggest end-use market for aluminium has been the transport sector. The transport industry plays an important role in the European Union economy. It accounts for 7% of GNP, 7% of jobs, 40% of investments by member states and 30% of energy consumption. Aluminium use yields, through its contribution to vehicle lightweighting, substantial energy savings and reduced emission and fuel consumption levels in today’s environmentally conscious society. Its strength and corrosion-resistance guarantee durability, reliability and security, coupled with cost-effectiveness. Its formability ensures complete flexibility of design and ease of handling, while its flawless aspect promises maximum aesthetic impact. Finally, its total recyclability allows the aluminium industry to fulfil its commitment to the principles of sustainable development. Today, aluminium is widely used in cars, trucks, buses, coaches, trains, metros, ships, ferries, aircraft and bicycles.

Transport Aeronautics The modern commercial aviation industry would never have succeeded without aluminium. The Wright brothers' first airplane, which flew in 1903, had a four-cylinder, 12-horsepower auto engine modified with a 30-pound aluminium block to reduce weight. Aluminium gradually replaced the wood, steel and other airplane parts in the early 1900s, and the first all-aluminium plane was built in the early 1920s. Since then, airplanes of all kinds and sizes have been made very largely of aluminium. For airplanes, aluminium is used because of its combination of light weight, corrosion resistance and the critical superior strength and mechanical properties which can be obtained in the 2xxx and 7xxx alloy series. Strong aluminium alloys take the extraordinary pressures and stresses involved in high altitude flying;

wafer thin aluminium panels keep the cold out and the air in. Many internal fittings like the seating on planes are made from aluminium or an aluminium composite in order to save weight and thus save fuel, reduce emissions and increase the aircraft's payload. Today, there are around 5,300 commercial passenger aircraft flying in the world, and many thousands of light aircraft and helicopters. Demand for commercial aircraft is forecast to rise by around 60% over the next decade. Aluminium is the primary aircraft material, comprising about 80 per cent of an aircraft's unladen weight. The standard Boeing 747 jumbo jet contains approx. 75,000 kg of aluminium. Because the metal resists corrosion, some airlines don't paint their planes, saving several hundred kgs of weight. For space exploration, such as in rockets, or satellites, aluminium is used for additional reasons. For example on satellites as highly reflective solar panels and on rockets as anodised heat shields.

Automotive Carl Benz produced the first combustion engine-driven car in 1886. Then, in 1899, a small sports car with an aluminium body was unveiled at the Berlin international car exhibition. In 1948, Land Rover made intensive use of aluminium outer skin sheets and, in 1953, the Panhard Dyna was the first volume-produced car to have an aluminium body. It was in 1965 that large-scale production of aluminium engine blocks began, while 1975 saw accelerated production of aluminium bonnets in US cars, due to stricter fuel consumption legislation resulting from the oil crisis. In 1994, Audi launched the all-aluminium passenger car in its Audi A8, which was followed in 1999 by the A2, geared for highvolume production. Today, many cars contain surprisingly significant amounts of aluminium, as designers become increasingly aware of the metal’s proven advantages. The Peugeot 307, for example, has an aluminium bonnet and the Jaguar XJ is the first all-aluminium body-in-white (BIW-the car’s metal structure) to employ structural adhesive bonding as one of its joining methods. Several high-performance sports cars, such as Ferrari and Lotus, are also produced in different variations and grades of aluminium. The European Aluminium Association, through its automotive department, has developed an online Aluminium Automotive Manual (AAM). This manual is a vast and comprehensive online information guide intended to provide technicians and engineers with information about aluminium for use in automotive applications. By logging on to the AAM website (see link below), you can discover the many and varied applications of aluminium in automotive and learn more about its material properties, its shaping, forming and joining technologies, and discern the unique aluminium design approach. You can also discover the main automotive applications by visiting the interactive automotive case study. By clicking on the left menu, you can also have a quick look at few examples of aluminium components used in automotive applications. Closure Sheet: The key in-service requirements for automotive closures (bonnets, boots, wings, rear quarter panels, doors) are panel bending stiffness and dent resistance, corrosion resistance and surface appearance. The main manufacturing requirements are good formability and joinability. Here we investigate the mechanical performance (bending stiffness and dent resistance) of two steels and an aluminum alloy, with respect to panel mass. Bending stiffness depends on Young's modulus, so changing alloy within steels or within Al alloys has little effect. Dent resistance requires a sufficiently high yield strength to withstand permanent deformation. Therefore Al alloys for closures are generally selected from the agehardened 6xxx series. Bending stiffness, dent resistance and panel mass all increase with panel thickness. Using aluminium sheet 1.44 times thicker than steel will result in 50% weight reduction for the same panel bending stiffness, without loss of dent resistance. Aluminium also competes favourably with steel on corrosion performance. However, the wider uptake of aluminium requires development of manufacturing technologies at a competitive cost, notably for forming and joining. One example of an efficient processing operation is the integration of forming, heat treatment and paint-bake cycle for 6xxx sheet.

The sheet is solution treated and naturally aged condition (T4), formed in this relatively soft condition, and finally age hardened (typically 160-180 °C for 30 minutes) to simultaneously increase the yield strength (for dent resistance) while curing the paint coating. Engine Block: luminium foundry alloys used in the production of such complex cast parts as engine blocks and cylinder heads must meet a combination of requirements which include low cost, castability, machinability, and moderate strength at elevated temperatures. Alloys commonly used in these applications include AA 319, AA 320, AlSi5Cu3, and AlSi6Cu4 (A23). These are all secondary hypoeutectic Al-Si alloys whose relatively high Cu content enables them to retain their strength at elevated temperatures as well as making them easily machinable. The parts may be T6 tempered but for many designs a T5 stabilizing temper is frequently sufficient. Some heads have even been put into service in the F-temper. These alloys have proven themselves over time to be the best engineering compromise for gasoline engines. Diesel engine cylinder heads may be cast out of AA 356, AA 357, AA 359, AlSi7Mg or AlSi9Mg. The higher resistance to cracking in the plastic regime that these alloys display enables them to survive the much harsher thermal fatigue loading conditions encountered in this application. There is some sacrifice in machinability (mainly burring) and added cost in heat treatment since a T6 or T7 temper is usually required. Cast aluminium cylinder heads and engine blocks generally weigh only half as much as ferrous castings Structure Sheet: luminium stamped sheet used for structural components requires high formability, strength/stiffness and corrosion resistance. Stamped sheet is used for higher volume production in preference to extruded "space-frame" structures. The stiffness of a given component is determined by its gauge (thickness) and the geometrical design - there is very limited scope for altering it through material properties (the Young modulus, E only ranges from 69-73 GPa for all aluminium alloys). The strength levels required are achieved using rolled and soft-annealed 5xxx (Al-Mg) sheet, which derive their strength through a combination of solute hardening and grain size hardening. Automotive Extrusions: luminium extrusions used for structural components require high formability, strength/stiffness and corrosion resistance. Extruded structures are used for lower volume vehicle builds as they are more cost-effective than stamped sheets. The stiffness is determined by the gauge (thickness) and design of the component - there is very limited scope for altering it through material properties. The strength levels required are achieved using precipitation hardened 6xxx (Al-Mg-Si) extrusions. Crash Box: Energy Absorption. Conflicting requirements with respect to saving weight and increasing vehicle crashworthiness at the same time, pose a major challenge in automotive design. Today, aluminium in its various product forms (sheet, extrusions, die castings) is an established automotive lightweight material offering excellent weight saving potential, including crashworthiness applications for passive vehicle safety. Modern ductile aluminium alloys have an outstanding ability to absorb impact energy in case of accidents. Combined with a good design, over 30 kJ per kg total weight of a structural component can be absorbed with aluminium. The underlying physical principle is illustrated by the relation for the energy absorption E of a rectangular tube: Bumpers: Aluminium bumpers are extruded from either 6xxx (Al-Mg-Si) or 7xxx (Al-Zn-Mg) heat-treatable alloys. The high strength 7xxx bumpers offer higher potential for weight reduction since thinner sections can be used. The required high-energy absorption capacity is met by special alloys and tempers combining good ductility and strength with extrudability and weldability. Also, the design of the extrusion plays an important role for the energy absorption in a collision, e.g. multihole extrusions have more favourable folding characteristics than single hole extrusions. The 6xxx alloys used are, for example EN AW-6008 and EN AW-6014 tempered to the T72 condition (overaged). Heat Exchangers: The high thermal conductivity of aluminium, combined with low density, makes it an ideal material for use in thermal management in the transport sector, especially automotive. About 80% of all vehicles contain aluminium heat exchangers.

Other Road Transport

Having made its debut in Parisian buses in 1910, aluminium was used for a variety of elements in road transport in the 1930s, when the industrial development of components actually began. The 1950s saw the first aluminium tankers, vans and tipping vehicles. For commercial vehicles, traditionally “heavy” vehicles, the advantages of aluminium were put to good use with the manufacture of the first aluminium systems to meet weight-sensitive transport requirements in the 1970s. By 1976, Alusuisse had produced the first all-aluminium truck prototype. Today, most tankers and silo semi-trailers are made entirely of aluminium. Aluminium is also frequently used for vans, tipping and self-discharging bodies. Without aluminium, the average articulated vehicle would be 800 kg heavier. The aluminium industry is active in developing new solutions for fleet operators. Whether used for the manufacture of trucks, trailers or buses, aluminium cuts down weight and brings substantial savings. The minimal additional investment for an aluminium vehicle is often offset by fleet operators in less than two years, through significant payload increase and reduced operating costs.

Rail Transport In the 1960s and 70s, aluminium made considerable progress in passenger railway cars where, from trams to trains, many aluminium components were introduced, like window frames and interior partition walls. Between the late 70s and the early 80s, when many European capitals developed their underground and tram networks, to link the main cities with their satellites, and when France developed its high speed trains, new technical challenges arose, that aluminium was able to meet: For underground and tramways, light vehicles were needed to lower running costs and improve acceleration. For the high speed trains, the choice of aluminium proved to be almost a must, as these trains needed to travel at more than 300 km/h on traditional railway tracks. A good example of aluminium's benefits in the public rail transport sector is the TGV-Duplex. Developed by Alstom by order of the SNCF, it weighs 12% less than the traditional TGV, transports 40% more passengers, and offers superior passive safety. For goods transport, an important use of aluminium occurs in countries such as the USA, Canada, and South Africa, which are rich in coal, metal ores, and other minerals, and which need to transport these materials over considerable distances between mines and production plants or port facilities. In these countries, aluminium railcars offer increased payloads that often compensate their extra purchasing costs in less than two years. Today, aluminium metros and trams operate in many European capitals and aluminium intercity trains are used all over Europe.

Sea Transport Soon after production of aluminium became possible on an industrial scale (just before the end of the 19th Century) a number of interesting possibilities arose for this class of materials, which were light and at the same time able to withstand mechanical stress. Above all, they possessed excellent resistance to corrosion in a marine atmosphere, thus reducing maintenance costs. Scottish shipbuilders Yarrow & Co were the first to construct a vessel from aluminium in 1895. The first applications designed and developed for mass production date back to the early post-war period when aluminium appeared in a number of parts of the deck and the bridges in cargo ships and military vessels. Starting in the 60s, aluminium spread also to passenger ships. The first important structural applications of aluminium were found in passenger hydrofoils. These were highly sophisticated vessels and the know-how developed during this technological experience formed a precious base for subsequent developments. A decisive turning point in the spread of aluminium in shipping came in the early 90s when European passenger and cargo sea transport saw a growth trend of the order of 15% per year, with peaks of 20%

in Spain, Finland and Sweden between 1990 and 1997 (Eurostat, 2001). The increase in traffic and the consequent birth of a class of private operators encouraged the diffusion of a competitive logic, based essentially on limiting the running costs of vessels and especially on the ability of shipping companies to effect more journeys in less time and with reduced consumption. In this competitive scenario, the demand for new vessels developed, based on high performance propulsion and on lightness. The use of aluminium combined with the use of water-jet propulsion made it possible to create a new category of vessels, the so-called high-speed ferries, single-hulled boats or more often catamarans, made entirely of aluminium. The same trend is noted in passenger vessels of between 30,000 - 70,000 gross tonnes and in cruising ships that are often built with steel hull and superstructures in aluminium. The application of aluminium in shipping extends also to other types of vessels. In fact aluminium now have a consolidated tradition lasting more than half a century in the construction of pleasure boats for sport and leisure, commercial passenger and cargo ships and military ships. Aluminium also has interesting applications in a similar field: offshore constructions. In oil drilling platforms, a large part of the superstructures and helicopter landing pads are entirely in aluminium.

Construction Aluminium is used in building and architecture for various reasons: 

Its light weight allows for easier rectification of structures for example façade panels, roofing, doors and windows in architecture, and ladders and platforms as building tools.



Its good inherent corrosion resistance and methods for protection such as anodising allow for durable outdoor exposure



Its attractive metallic appearance and the methods for colouring is ideal for decorative design



These properties in combination with the good strength-to-weight ratio that can be obtained, results in various day to day applications of aluminium, mainly of the 1xxx, 3xxx and 5xxx alloy series for sheet products and 6xxx series for extruded products, in our houses, offices, public buildings and their construction.

Note also that metallic aluminium in "massive" form will not burn. Further, its relatively low melting point (660 °C) means it will "vent" early during a severe fire, releasing heat and thereby saving lives and property. Construction and demolition waste products represent a growing challenge for modern industrial societies. The depositing or incineration of most types of materials can lead to air, water and soil pollution. This is not the case for aluminium, which even if inadvertently dispersed in the environment does not have harmful side-effects. Therefore, aluminium recycling not only has important economic implications but also contributes to environmental protection. A study has demonstrated that about 95% of aluminium building products are recycled at their end-of-life thanks to the high value of the aluminium scrap.

Architectural Sheet Aluminium alloys in sheet form are used for a variety of applications on buildings, such as roofing and external cladding. Such applications make use of the material's durability, being hard wearing and resistant to corrosion. The sheet can be used bare, but for many applications a paint coating is applied by the sheet supplier to increase protection from the environment and for aesthetic appearance. For some applications, the sheet surface is anodised to produce a decorative surface finish. Good surface appearance is obviously a critical requirement of these products, but some strength is generally required for in-service performance as well as formability, for example, to enable the sheet to be shaped into profiled panels for rigidity. Low strength commercial purity alloys such as EN AW-1200 are used for some applications (e.g. flashing), but generally higher strength alloys of the 3xxx series are used.

5xxx series alloys are employed where high strength is a particular requirement or corrosion resistance is needed, for example in marine environments. Depending on the may be used in the soft-annealed O-temper, where dispersion-hardening and strengthening alone determine the mechanical properties, or in a range of work-hardened

where greater product, sheet solid solution tempers.

Packaging Aluminium packaging via its unique combination of properties contributes to the efficient fabrication, storage, distribution, retailing and usage of many products Aluminium is used in packaging for various reasons: 

Its low density is beneficial for the transport of packaged goods and for the eventual disposal of spent products;



Its inherent inertness and non-toxicity, lack of taste and odour and impermeability to liquids, solids, gasses, or light allows the packaging, and durable protection of foodstuffs, beverages, pharmaceuticals, cosmetics etc. It also withstands both heat and cold.



its good formability for alloys mainly from the 1xxx and 3xxx series, while still being of sufficient strength is ideal for the production of foil (1xxx series), laminated closures (1xxx series), round cans (3xxx and 5xxx series) or other thin sheet packaging containers and tubes.



Its recycling is cost effective and helps reduce energy consumption, raw materials and ultimate disposal.

The aluminium industry has a long tradition of collecting and recycling used aluminium products; the high economic value of used aluminium packaging is an incentive to continuous improvement of recycling: an average of 58% of beverage cans were recycled in 2007 in Europe. Aluminium can contain, protect, decorate or dispense products as diverse as soft drinks and soaps, pet foods and snack foods, tobacco and toiletries, chocolates and chilled foods, tablets and takeaway meals – even tennis balls and welding rods. Aluminium packaging has become part of everyday life. The aluminium beverage can is a nice example of how a well-chosen combination of alloy properties can result in a globally used product.

Electrical and Thermal Applications The use of aluminium in electrical and thermal applications is due to the good electrical and thermal conductivities of the alloys mainly from the 1xxx (for electrical) and 3xxx, 5xxx and 6xxx series (for thermal), but again its light weight, favourable strength-to-weight ratio and a durable corrosion resistance are added benefits compared to other materials. Aluminium or aluminium alloy electrical conductors are now widely used in the following areas: Overhead lines, electrical energy distribution and transport cables, and energy cables for industrial use. Almost all electric lights, motors, appliances and power systems depend on a vast grid of aluminium wire. Around the world most high-voltage overhead transmission and distribution lines and many underground lines are made of aluminium. Aluminium replaced copper in high-voltage transmission lines after 1945 and today is the most economical way to transmit electric power. Aluminium is also widely used in "switchyards" or substations where electricity is stepped down to lower voltages for local distribution. Many substations are almost all aluminium. The power systems of the world's largest buildings are made of aluminium.

Since the 1950s aluminium has practically replaced brass as the standard base for the electric light bulb. Thousands of television antennae and many satellite dishes are also made of aluminium. For electrical cables the mechanical properties are very important as illustrated in the dedicated case study on electrical cables. Additionally, the use of aluminium for electrolytic capacitors is also a large application area. The possibility of rolling aluminium into thin foil and being able to change its capacitance through etching and anodising is a major benefit as illustrated in the section on electrolytic capacitors under dielectric surface properties. Due to its high thermal conductivity, aluminium is also very well suited for heat exchanger tubes, connections and brazing sheet. Aluminium brazing sheet is an innovation allowing the complicated design of the heat exchanger to be assembled in one production step, as illustrated in the dedicated case study on heat exchangers.

Aluminium Electrolytic Capacitors In an electrolytic capacitor there is an anodised aluminium foil as one plate (the anode), and an electrolyte replacing the second plate (cathode). There is a second metallic electrode for the electrical contact (cathode foil). The anodisation layer is the dielectric. The original wet electrolytic capacitors comprised a lead or aluminium can containing the aqueous electrolyte and the loosely coiled anode foil. The dry types of electrytic capacitors contain a viscous solution of e.g. boric acid in glycerol or ethylene glycol or, more recently introduced, dimethyl formamide based electrolytes (extending the operation temperature range of the capacitors to between −55 °C and 125 °C). The construction method is to sandwich a strip of porous paper soaked in the electrolyte between the anode and the auxiliary plain cathode foil, rolled up and placed in a metal can or cardboard tube with external connections. Impurities can be a source of electronic leakage current, thus reducing the dielectric ability of the film. Thus capacitor foil is made out of high purity aluminium, mostly 99.99%.

Conductors for Overhead Power Lines High voltage overhead power lines must satisfy many simultaneous requirements: minimum electrical resistance (to reduce losses), safe clearance above the ground, sufficient strength for the applied loads, and practical cost for the 100s or 1000s of km typically installed. A wide variety of cable specifications are available to meet the demands for different current carrying capacity in many different climates and types of terrain. Long-distance overhead conductors use aluminium in preference to copper - the lower electrical conductivity being more than compensated by the lower density and cost. In composite steel-Al cables, the steel carries most or all of the mechanical load, and the Al the electrical current. Aluminium is often now used throughout, serving both electrical and mechanical purposes. Overhead cables range in size from 5-40 mm in diameter, using layered helical windings, with the twist direction alternating between layers. The individual strands are typically 2-4 mm in diameter, convenient for wire drawing and winding. In reinforced cables, the inner strands predominantly carry the load.

Domestic Applications

he use of aluminium in domestic and office applications is often due to the highly decorative and fashionable design appearance of aluminium, for example in kitchens, aluminium sheets above stoves or around ovens or the use of design aluminium handles on doors. Of course for actual furniture, such as tables and chairs, the mechanical properties are also very important. For household appliances such as irons and cooking utensils, the thermal properties are equally determining; for example in the case of an iron, anodised aluminium soles are a durable solution both in terms of heat resistance and for hardness, wear and scratch resistance. For cooking tools, high thermal conductivity is a prerequisite additional to the lighter weight compared to copper or steel pots and pans. For lighting applications, it is the high inherent reflectivity of aluminium which determines its use, in addition to its low density. Hence for various objects: furniture, utensils and decorations, a combination of requisite properties explains why aluminium is so common in our everyday life.

Aluminium in Structural Applications The use of aluminium alloys in structural applications has grown considerably in the past few decades. In transportation, the low density of aluminium, resulting in a high strength-to-weight ratio, makes it a favourable material for aircraft, high speed trains and ferries. In building and civil engineering, low density is sometimes the determining factor in the choice of aluminium; e.g. movable bridges, helicopter decks on offshore platforms, etc. However, other favourable properties such ascorrosion resistance, easy shaping of profiles by extrusion, and aesthetics are often more important.

Why is aluminium used in structures? 

To achieve lightweight structures



To aim at sustainable structures requiring less maintenance



Good recycling opportunities



Knowledge of aluminium structural behaviour at similar level to steel



Design rules available in Eurocode 9

In this module, three sections have been developed in order to illustrate the design and use of aluminium alloys in structural applications:

Manufactura,

ingeniería y tecnología. Escrito por Serope Kalpakjian,Steven R. Schmid,Ulises

https://books.google.es/books? id=gilYI9_KKAoC&pg=PA157&lpg=PA157&dq=aluminio+aleaciones+y+usos&source=bl&ots=mo5RBYot Oy&sig=239exOB6z00XBCXk5w8Ukn9q27E&hl=es&sa=X&ei=JyEdVaSBMYjbUGIgMgI&ved=0CCYQ6AEwATgU#v=onepage&q=aluminio%20aleaciones%20y%20usos&f=false Los factores de importancia en la selección de aluminio y de sus al3eaciones osn su elevada relación resistencia a peso, su resistencia a al corrosión frente a muchos productos químico9s, su elevada odneductividad térnmica y eléctrica, su no toxicidad, su reflectividad, su apariencia y su facilidad de conformado y de maquinabilidad ; también son antimagnéticos. Los usos principales del alumihio y de sus aleaciones, en orden decreciente de consumo, es en recipientes y empaques (latas de alumini y hoja de aluminio(, en edificios y otros tipòs de construcciónes, en eln transporte (aplicaciones en aeronaves y aerospaciales, autobus3es, automóviles, carros de ferrocarril y equipo marino), en ap,.icaciones eléctircas (conductores eléctricos económicos y no magnéticos), en productos durarderos para el consumidor (aparatos domésticos, utensilios de cocina y muebles(), y en herramientas portátiles. Práctrivamente todo el alambrado de transmisión de alto voltaje está hecho en aluminio. En sus componentes estructurales (que soportan carga), el 82% de una aeronave _Boeing 747 y el 79% de una aeronave Boeing 757 es aluminio.

Las aleaciones de aluminio están disponibles como productos de laminación, es decir, como productos en bruto presentados en varias formas mediante laminado, extrusión, estirado y forjado. Están disponibles lingotes de aluminio para la fundici´`ohn, como aluminio en polvo para aplicaciones de metalurgia de povos. Se han desarrollado técnicas mediante las cuales la mayor parte de las aleaciones de aluminio pueden ser maquinadas, formadas y soldadas con relativa facilidad. Hay dos tipos de aleaciones del aluminio forjados: a)

Aleaciones que pñeudan ser endurecidas por trabajo en frío y que no es posibles tratarlas térmicamente, y

b)

Aleaciones que pueden ser endurecidas por tratamiento térmico.

Designacion de las aleaciones del aluminio en bruto. Las aleaciones de aluminio en bruto se identifican mediante cuatro dígitos y una designación de temple mostrando el estado del material., SE identifica el elemento principal de las aleaciones mediatne el primer´dígito., Este es el sistema: 1xxx _ Aluminio comercialmetne puro – excelente resitencia ala corrosión, elevsada conductividad eléctrica y térmica, buena capacidad de trabajo, baja resistencia, no es tratable ´termicamente. 2xxx – Cobre – elevada relación restitencia a peso, baja resitencia ala corrosión, tratable térmicamente. 3xxx – manganeso – buena capa idazd dde trabajo, resitencia moderada, generalemnte no es tratable térmicamente. 4xxx – silicio – menor punto de fusión, forma una película de óxido de color de greis oscuro a negro carbón, generalmente no tratable térmicamente. 5xxx magnesio –buena resistenca ala corrosión y buena soldabilidad, resitencia mecánica de moderada a alta, no es tratable térmicamente. 6xxx – magnesio y silicio . resistencia media, buena formabilidad, maquinabilidad, soldabilidad y resistencia a la corrosión, tratable térmicamente 7xxx- zinc - resistencia demoderada a muy alta, tratable térmicamente. 8xxx – otro elemento. En estas designaciones el segundo dígito indica modificaciones de la aleación. Para la serie 1xxx, el tercero y cuarto dígitos representan la cantidad mínima de aluminio de la aleación . por ejemplo 1050 indica un mínimo de 99,50% de aluminio. En otras series el tercero y cuarto dígito identifican las diferentes aleaciones en el grupo sin un significado numérico. Designación de las aleaciones de aluminio fundidas. Las designaciones de las aleaciones de aluminio fundidas también están formadas por cuatro dígitos. El primer dígito indica el grupo de aleación principal como sigue: 1xx.x – Aluminio (99,00% mínimo) 2xx.x – Aluminio-cobre 3xx.x – Aluminio-silicio con cobre y/o magnesio 4xx,.x – Aluminio-silicio 5xx.x – Aluminio.magnesio 6xx.x Serie no utilizada 7xx.x Aluminio-zinc 8xx.x Aluminio-estaño

En la serie 1, los segundos y tercer dígitos indican el contenido mínimo de aluminio, igual que ocurre en los terceros y cuartos dígitos delaluminio forjados. Oara las otras series, los dígitos segundos y terceros no tienen un significado numético. El cuarto dígito, a la derecha del punto digital, indica la forma del producto. Designaciones de temple. Las designaciones de temple para le aluminio tanto en bruto como fundido son como sigue: F – tal y como se fabrica, mediatne trabajo en frío o en caliente o mediante el colado O – recocido, del estado de trabajo en gfrío o colado H – endurecido por deformación por trab ajo en fgreío, para productos forjados únicamente T – tratado térmicamente W – tratado por solución únicamente (temple inestable)

Producción El aluminio se produjo por primera ve3z en 1825. Es el elemento metálico más abundante, representando aproximadamente 8Ç% de la corteza terrestre. Es producido en cantidades superadas únicamente por la producci´`on de hierro,. Elmineral principal de aluminio es la auxita, que es un óxido de alumninio hidratado (que contiene agua) e incluye otros óxidos. Una vez lavados la arcilla y la tierra, el mineral es teriturado en polvo9 y después tratado con sosa caústica caliente (hidróxido de sodio) para eliminar las impurezas,. La akúmina (óxido de aluminio) es extraída de esta solución y después es disuelta en unbaño fundido de fluoruro de socio y de fluoruyro de aluminio a 940ºC-980ºC. Esta mezcla se somete a una electrólisis por corriente directa. Se forma el metal de aluminio en el cátodo, en tanto que se libera oxígeno en le ánodo,. El aluminio comercialmente puro tiene hasta el 99,99% de alumihnio y se conoce también en la industria como aluminio de “cuatro nueves”. El proceso de producción consume gran cantidad de electricidad contribuyendo por tanto de manera importante al costo del aluminio. Aluminio poroso,. Se han producido recientemente bloques de aluminio que son 37% más ligeros que el aluminio sólido y tienen una permeablididad (microporosidad) uniforme,. Esta característica permite syu uso en aplicaciones donde se deben mantener o un vacío o una presióni diferencial. Ejemplos serían la sujeción por vacío de dispositivos de ensamble y automatización y el formado por vacío, es decir, el termoformado de plásticos,. Estos bloques están formados de 70 a 90% de povo de aluminio; el resto es resina epóxica, Oyueden ser maquinados con relativa facilidad y se pueden unir utilizando adhesivos.