Aluminium developments

Alloy System (The Aluminium Development Association, London 1961)... 

H. W. L. Phillips Equilibrium Diagrams of Aluminium 1.19 Alloy System (The Aluminium Development Association, London 1961)... 

The growth of hydrated aluminium oxides was extensively studied and reported by Vedder and Vermilea. " Aluminium develops surface oxides that change with the temperature of treatment. Below 40 °C, the surface oxide is dominated by bayerite (Al(OH)3), but as the temperature increases towards the boiling point of water the amount of pseudoboehmite increases. Pseudoboehmite is an aluminium hydroxyl-oxide with varying amount of waters of hydration, with the formula AiPj uHp. 

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

Phi] Phillips, H.W.L., Al-Cr-Fe , in Equilibrium Diagrams of Aluminium Alloy Systems. Information Bulletin 25 , Aluminium Development Association, London, 1-78 (1961) (Phase Diagram, Review, 1)... 

This paper compares experimental data for aluminium and steel specimens with two methods of solving the forward problem in the thin-skin regime. The first approach is a 3D Finite Element / Boundary Integral Element method (TRIFOU) developed by EDF/RD Division (France). The second approach is specialised for the treatment of surface cracks in the thin-skin regime developed by the University of Surrey (England). In the thin-skin regime, the electromagnetic skin-depth is small compared with the depth of the crack. Such conditions are common in tests on steels and sometimes on aluminium. 

The developed method is used in eddy current defectoscopes like Zond VD used for detecting corrosion spots in the body of the plane through aluminium cover, cracks detecting in helicopter blades under dielectric covers up to 8-10 mm thick, in pipelines under protective covers up to 10 mm thick, etc... 

The way in which materials are used in a developed nation is fairly standard. All consume steel, concrete and wood in construction steel and aluminium in general engineering copper in electrical conductors polymers in appliances, and so forth and roughly in the same proportions. Among metals, steel is used in the greatest quantities by far 90% of all the metal produced in the world is steel. But the non-metals wood and concrete beat steel - they are used in even greater volume. 

Aluminium-based metals are the obvious choice" (Table 1.4) - they are light, corrosion resistant and non-toxic. But it took several years to develop the process for forming the can and the alloy to go with it. The end product is a big advance from the days when drinks only came in glass bottles, and has created a new market for aluminium (now threatened, as we shall see in Chapter 21, by polymers). Because aluminium is... 

Today the sulphonation route is somewhat uneconomic and largely replaced by newer routes. Processes involving chlorination, such as the Raschig process, are used on a large scale commercially. A vapour phase reaction between benzene and hydrocholoric acid is carried out in the presence of catalysts such as an aluminium hydroxide-copper salt complex. Monochlorobenzene is formed and this is hydrolysed to phenol with water in the presence of catalysts at about 450°C, at the same time regenerating the hydrochloric acid. The phenol formed is extracted with benzene, separated from the latter by fractional distillation and purified by vacuum distillation. In recent years developments in this process have reduced the amount of by-product dichlorobenzene formed and also considerably increased the output rates. 

The early history of ionic liquid research was dominated by their application as electrochemical solvents. One of the first recognized uses of ionic liquids was as a solvent system for the room-temperature electrodeposition of aluminium [1]. In addition, much of the initial development of ionic liquids was focused on their use as electrolytes for battery and capacitor applications. Electrochemical studies in the ionic liquids have until recently been dominated by work in the room-temperature haloaluminate molten salts. This work has been extensively reviewed [2-9]. Development of non-haloaluminate ionic liquids over the past ten years has resulted in an explosion of research in these systems. However, recent reviews have provided only a cursory look at the application of these new ionic liquids as electrochemical solvents [10, 11]. 

The development of acidity within an occluded cell is by no means a new concept, and it was used by Hoar s as early as 1947 in his Acid Theory of Pitting to explain the pitting of passive metals in solutions containing Cl ions. According to Hoar the Cl ions migrate to the anodic sites and the metal ions at these sites hydrolyse with the formation of HCl, a strong acid that inhibits the formation of a protective film of oxide or hydroxide. Edeleanu and Evans followed the pH changes when aluminium was made anodic in Cl solutions and found that the pH decreased from 8-8 to 5-3. 

With increasing purity of aluminium, greater resistance to corrosion is developed. On high-purity materials, however, any pits which develop are likely to be deeper though fewer in number than those formed in more impure metal. In some special applications, notably in contact with ammonia solutions or pure water at elevated temperatures and pressures, the iron and silicon present in commercial-purity metal are beneficial and retard corrosion. Up to about 5% magnesium improves the corrosion resistance to sea-water. 

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