Applications of aluminium

Immersion tests in seawater at many places, some of which have exceeded 10 years, as well as more than 50 years of experience with marine applications of aluminium demonstrate that casting alloys without copper of the 40000 series A-S7G (42100), A-SIOG (43100) the 50000 series A-G3T (51100), A-G6 (51300), as well as wrought alloys of the 5000 and 6000 series have an excellent resistance to corrosion in the marine environment and seawater. 

These alloys can be used with no protection, except when fouling must be prevented. The use of antifouling paints containing copper or mercury must be absolutely prohibited, because they induce pitting attacks (by reduction of copper and mercury cations on aluminium) that can jeopardise the use of the aluminium equipment. Antifouling paints based on organo-tin compounds may be used, unless prohibited by regulations. 

Copper-containing alloys of the 2000, 6000 and 7000 series, as well as copper-containing casting alloys of the 20000 series (A-U5GT) and the 40000 series (A-S9U3) cannot be used without protection paint, anodisation, etc. They are in fact much too prone to pitting corrosion as well as to other forms of corrosion (exfoliation, stress corrosion). 

Aluminium has a very large number of marine applications [23]. 

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Copper alloys in wrought or cast form are used for other purposes in ships and other marine installations, such as for propellers bearings, valves and pumps. One widespread application of aluminium-brass is its use for heating coils in tankers carrying crude oil or petroleum products. Some corrosion problems encountered in this and other applications on board ship have been described by Gilbert and Jenner . 

Sprayed, vacuum-deposited and plated coatings can be applied to most metals and to many non-metals, e.g. vacuum deposition is applied to many substrates including plastics spray application can be used for coating fabric, plastic and paper. Hot dipping and other diffusion processes are dependent on the nature of the substrate for the properties of the coating. Most commercial applications of aluminium coatings are on iron and steel with smaller quantities applied to aluminium alloys and plastics. 

Notes on the applications of aluminium alloys. Commercial aluminium alloys are discussed in next section. 

Furuno, T., Uehara, T. and Jodai, S. (1991). Combinations of wood and silicate I. Impregnation by water glass and applications of aluminium sulfate and calcium chloride as reactants. Mokuzai Gakkaishi, 37(5), 462 72. 

Polymeric varieties of aluminium phosphates have found important applications in cements and in the bonding of refractories. The basis of phosphate bonding is the formation of polymers on dehydration, which may be poly or metaphosphates, or ultimately AIPO4 (5.135) (Chapter 12.10). The many applications of aluminium orthophosphates include dental cements, metal coatings, binders and adhesives and corrosion-inhibiting pigments (Chapter 12.8). 

The applications of aluminium and its alloys are depending on the properties. In most cases, mechanical properties are an important criterion for assessing the suitability of an A1 alloy for a specific application. Other properties, such as electrical conductivity or corrosion resistance, may also be included in the assessment process. 

The application of aluminium hydroxide as selective sorbent of lithium salts from brines and technical solutions... 

Due to the various industrial applications and economic importance of alutninium and its alloys, its protection against corrosion has attracted much attention (Aballe et al., 2001 Cheng et al., 2004 Hintze and CaUe, 2006). Most aluminium alloys have good corrosion resistance towards natural atmospheres and other environments, because alutninium alloy surfaces are covered with a natural oxide film of thickness about 5 nm (KUckic et al., 2000). However, in the presence of aggressive ions, like chloride, the protective layer can be locally destroyed and corrosive attack takes place (Kliskic et al., 2000). Yet, if correctly protected, applications of aluminium alloy may be more reliable and have long service life. 

It is explored and proven in this research that NH, VL and TS carry tremendous potential for industrial usage. Unlike the pure synthetic product that requires enormous investment scale NH, VL and TS can be produced at any type of industrial scale, which is potentially capable of eradicating the disparity among the communities, especially in the third world. Furthermore, the potential usages of these natural products discussed in this research are in line with the recent trend of the environment-friendly concept. However, resolution of the problem of whether the origin of these effects is associated with an application of aluminium alloys must await the results of further experimental studies. 

Another animal experiment in chinchillas found that application of aluminium acetate (0.5%)/benzalkonimn chloride (0.03%) otic solution causes hearing loss when a tympanic membrane perforation exists [54 ]. 

Whenever there is a problem related to heat exchange, the use of aluminium is always taken into consideration, under the condition, of course, that the medium is appropriate when liquid-liquid or liquid-gaseous exchange is envisioned. There are many applications of aluminium heat-exchangers cars, commercial vehicles, refrigerators, air conditioning, desalination of seawater, solar energy, coolers in electronic devices, etc. 

Since it is not possible to deal with every application of aluminium and its alloys because there are so many, the principal applications are discussed with classic choices of alloys and semi-products (Table A.5.2). 

Table A.5.2. Typical applications of aluminium and aluminium alloys...

For a very long time, galvanic corrosion of aluminium in contact with other metals was a major concern to users, to such an extent that it slowed down the development of applications of aluminium whenever the issue of its behaviour in contact with other metals was raised. Nowadays, it is surprising to discover the extensive precautions that were taken in former times with heterogeneous assemblies exposed to ambient atmosphere. 

This is the oldest known application of aluminium in buildings that is still in service. The dome was covered in 1897 (Figure C.5.1). In order to obtain a satisfactory light level in the choir of the San Gioacchino church in Rome, the architects put numerous windows in the dome, which needed to be lightened. For this purpose, aluminium was chosen instead of lead, which had been commonly used as a roofing sheet for this type of building. 

The development of applications of aluminium in constructions such as metallic fittings, foldable walls, shop equipment, urban furniture stems from the excellent resistance to atmospheric corrosion of anodic layers. These layers aim at maintaining the surface appearance over a long period of time by preventing blackening and pitting corrosion. 

Since the beginning of the 1950s, marine applications of aluminium have been widely developed. 

The application of aluminium alloys to marine uses. Aluminium Development Association London, 1948. 

The dissolution rate of aluminium increases with the acid concentration (Table E.5.3) [5, 6], and very sharply increases with temperature (Table E.5.4) [5]. For a given concentration, it is much smaller than what is observed with hydrochloric acid. As a consequence, there are a few applications of aluminium in contact with diluted sulphuric acid such as cathodes of electrolysis cells for the production of zinc sulphate [7]. 

There is a wide range of applications of aluminium alloys such as 3003, 5754, 5083, 5086, 6060, 6061, A-S7G (42000), A-S13 (44100) in the presence of sodium chloride. They are used in the food industry (see Chapter G.6), for example, as saucepans for cooking food in salt water containing about 10 g l of NaCl (which may contain small impurities such as sodium sulphate and nitrate), trays for the production of salted food and in the canning industry. Aluminium does not alter the taste or colour of salt solutions. 

The first applications of aluminium in the food industry date back to the early 20th century, in breweries and as kitchen utensils for household and industrial use, where it has progressively replaced tin-coated copper. 

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